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Arrhythmias

Arrhythmias

Arrhythmia or cardiac arrhythmia, means “abnormal heart rhythm” or it’s a heart condition where your heart beats abnormally. Arrhythmia can be caused a problem with your heart’s electrical signals and conduction system that coordinate your heartbeats. Arrhythmias are caused by a problem in the heart’s electrical conduction system, which can make your heart beat too slowly (bradycardia), too fast (tachycardia) or irregularly (fibrillation). There are many types of arrhythmias, depending on what part of your heart is affected and whether they cause a slow (bradycardia), fast (tachycardia), or irregular heart rate (fibrillation). Arrhythmias may happen in the atria (upper chambers of the heart) or the ventricles (lower chambers of the heart).

An arrhythmia occurs when:

  • Your heart’s natural pacemaker, also known as the sinus node or sinoatrial (SA) node located in the right upper chamber (right atrium), develops an abnormal rate or rhythm.
  • Your heart’s normal electrical conduction pathway is interrupted or changed.
  • Another part of your heart takes over as the heart pacemaker and can fire automatically and start an electrical activity. This electrical activity can interrupt the normal order of the heart’s pumping activity.

The main types of arrhythmia are:

  • Atrial fibrillation (AF or afib) – this is the most common type, where the heart beats irregularly and faster than normal
  • Atrial flutter is usually a fast heart rhythm where the top chambers of the heart (the atria) contract at a very fast rate compared to the lower chambers (the ventricles). This can cause the top chambers (the atria) to beat extremely fast, sometimes up to 300 beats per minute (bpm)
  • Supraventricular tachycardia (SVT) – is a very fast heart rhythm. There are different types of supraventricular tachycardia (SVT). Most are due to electrical impulses not traveling normally from the top chambers of the heart (the atria) to the bottom chambers of the heart (the ventricles).
  • Bradycardia – the heart beats more slowly than normal, that is a resting heart rate that is slower than 60 beats per minute (<60 bpm)
  • Sick sinus syndrome also called tachybrady syndrome, causes periods of very fast or slow heart beats
  • Heart block – heart blocks are caused by a delay or blockage in your heart conduction system between the top chamber (the atria) and bottom chambers of the heart (the ventricles) which can cause a slow heart rate and can cause people to collapse
  • Ventricular fibrillation (VF or vfib) – a rare, rapid and disorganised rhythm of heartbeats that rapidly leads to loss of consciousness and sudden death if not treated immediately.

Arrhythmias may occur at any age, although the condition is more common in adults.

Arrhythmias are investigated much like other health conditions. Your doctor will likely inquire about your medical history to understand everything possible about the arrhythmia, its origins and implications.

You may be asked questions such as:

  • Are you aware of unusual heartbeats?
  • How long has this been happening?
  • Does anything bring on the arrhythmia?
  • Is there anything you can do to make it stop?
  • How fast is your heartbeat?
  • Do you feel weak, lightheaded or dizzy?
  • Have you ever fainted?

Your doctor may also ask about prescribed and over-the-counter medicines because some may make arrhythmias worse.

Once your doctor has documented that you have an arrhythmia, he/she will need to find out whether it’s abnormal or merely reflects the heart’s normal processes. He or she will also determine whether your arrhythmia is clinically significant – that is, whether it causes symptoms or puts you at risk for more serious arrhythmias or complications of arrhythmias in the future. If your arrhythmia is abnormal and clinically significant, a treatment plan will be developed.

When to see your doctor

If you feel like your heart is beating too fast or too slowly, or it’s skipping a beat, make an appointment to see a doctor. Seek immediate medical help if you have shortness of breath, weakness, dizziness, lightheadedness, fainting or near fainting, and chest pain or discomfort.

You should see your doctor about your symptoms if:

  • your palpitations last a long time, don’t improve or get worse
  • you have a history of heart problems
  • you’re concerned about the palpitations.

You should call your local emergency services number immediately for a medical assistance and an ambulance if:

  • along with palpitations, you start to feel short of breath, have chest pain or feel faint or dizzy.

A type of arrhythmia called ventricular fibrillation, vfib or VF can cause a dramatic drop in blood pressure. Collapse can occur within seconds and soon the person’s breathing and pulse will stop. If this occurs, follow these steps:

  • Call your local emergency services number immediately for a medical assistance and an ambulance
  • If there’s no one nearby trained in cardiopulmonary resuscitation (CPR), provide hands-only CPR. Push hard and fast on the center of the chest at a rate of 100 to 120 compressions a minute until paramedics arrive. You don’t need to do rescue breathing.
  • If you or someone nearby knows CPR, start CPR. CPR can help maintain blood flow to the organs until an electrical shock (defibrillation) can be given.
  • If an automated external defibrillator (AED) is available nearby, have someone get the device and follow the instructions. An AED is a portable defibrillation device that can deliver a shock that may restart heartbeats. No training is required to operate an automated external defibrillator (AED). The AED will tell you what to do. It’s programmed to allow a shock only when appropriate.

What is a normal heart rate?

Your heart rate or pulse, is the number of times your heart beats per minute (bpm). Normal heart rate varies from person to person. For most healthy adult women and men, if you’re sitting or lying and you’re calm, relaxed and aren’t ill, your resting heart rate is normally between 60 (beats per minute) and 100 (beats per minute) 1.

According to the National Institute of Health, the average resting heart rate:

  • for an infant, the heart beats 100 to 190 times a minute on average
  • for children 10 years and older, and adults (including seniors) is 60 – 100 beats per minute (bpm)
  • for well-trained athletes is 40 – 60 beats per minute (bpm).

Other Factors that can affect your heart rate

  • Air temperature: When temperatures (and the humidity) soar, the heart pumps a little more blood, so your pulse rate may increase, but usually no more than five to 10 beats a minute.
  • Body position: Resting, sitting or standing, your pulse is usually the same. Sometimes as you stand for the first 15 to 20 seconds, your pulse may go up a little bit, but after a couple of minutes it should settle down.
  • Emotions: If you’re stressed, anxious or “extraordinarily happy or sad” your emotions can raise your pulse.
  • Body size: Body size usually doesn’t change pulse. If you’re very obese, you might see a higher resting pulse than normal, but usually not more than 100.
  • Medication use: Medications that block your adrenaline (beta blockers) tend to slow your pulse, while too much thyroid medication or too high of a dosage will raise it.
  • Energy drinks.
  • Caffeine in beverages and foods.

Is resting heart rate different by age?

For most of adults, between 60 and 100 beats per minute (bpm) is normal 1. Your heart rate can be affected by factors like stress, anxiety, hormones, medication, and how physically active you are. An athlete or more active person may have a resting heart rate as low as 40 beats per minute.

When it comes to resting heart rate, lower is better. It usually means your heart muscle is in better condition and doesn’t have to work as hard to maintain a steady beat. Studies have found that a higher resting heart rate is linked with lower physical fitness and higher blood pressure and body weight 2.

What is sinus tachycardia?

Tachycardia is a resting heart rate that is faster than 100 beats per minute. Sinus tachycardia is when your heart beats in a regular way faster than 100 beats per minute (bpm).

If you have sinus tachycardia it doesn’t mean there’s something wrong with your heart and you might not need treatment. Sometimes it can be due to an underlying medical problems, such as an abnormally high level of thyroid hormones called hyperthyroidism, which you may need treatment for, so your doctor might want to send you for further tests to find out more.

What is sinus bradycardia?

Bradycardia is a resting heart rate that is slower than 60 beats per minute. Sinus bradycardia is when your heart beats in a regular way below 60 beats per minute (bpm).

If you have sinus bradycardia it doesn’t mean there’s something wrong with your heart and you might not need treatment. Active people often have a lower resting heart rate (as low as 40 bpm) because their heart muscle is in better condition and doesn’t need to work as hard to maintain a steady beat. A low or moderate amount of physical activity doesn’t usually change the resting pulse much. As you age, changes in the rate and regularity of your pulse can change and may signify a heart condition or other condition that needs to be addressed.

Sometimes a sinus bradycardia can be due to an underlying condition which you may need treatment for, so your doctor might want to send you for further tests to find out more.

Also if you have a low heart rate and are experiencing symptoms like fainting, fatigue and dizziness then you should make an appointment with your doctor.

What is a target heart rate?

Your target heart rate is between 50% and 70% of your maximum heart rate. The general formula for calculating your maximum heart rate is 220 minus your age. You should aim to exercise with your heart rate between these two figures. Your target heart rate will make sure you increase your fitness and strength safely.

If you have a heart condition, check with your doctor before doing any new exercises, in case they aren’t suitable. You should also warm up and cool down before and after exercising to avoid injury to your muscles and protect your heart from speeding up or slowing down too fast.

For moderate-intensity physical activity, your target heart rate should be between 64% and 76% of your maximum heart rate 2, 1. This maximum rate is based on the person’s age. To estimate your maximum age-related heart rate, subtract your age from 220. For example, for a 50-year-old person, the estimated maximum age-related heart rate would be calculated as 220 – 50 years = 170 beats per minute (bpm). The 64% and 76% levels would be:

  • 64% level: 170 x 0.64 = 109 bpm, and
  • 76% level: 170 x 0.76 = 129 bpm

Thus, moderate-intensity physical activity for a 50-year-old person will require that the heart rate remains between 109 and 129 bpm during physical activity.

For vigorous-intensity physical activity, your target heart rate should be between 77% and 93% of your maximum heart rate 2, 1. You can estimate your maximum heart rate based on your age. To estimate your maximum age-related heart rate, subtract your age from 220. For example, for a 35-year-old person, the estimated maximum age-related heart rate would be calculated as 220 – 35 years = 185 beats per minute (bpm). The 77% and 93% levels would be:

  • 77% level: 185 x 0.77 = 142 bpm, and
  • 93% level: 185 x 0.93 = 172 bpm

This shows that vigorous-intensity physical activity for a 35-year-old person will require that the heart rate remains between 142 and 172 bpm during physical activity.

What’s the difference between blood pressure and pulse?

While your blood pressure is the force of your blood moving through your blood vessels, your heart rate is the number of times your heart beats per minute. They are two separate measurements and indicators of health. For people with high blood pressure (hypertension), there’s no substitute for measuring blood pressure.

Does high blood pressure increase heart rate?

Heart rate and blood pressure do not necessarily increase at the same rate. A rising heart rate does not cause your blood pressure to increase at the same rate. Even though your heart is beating more times a minute, healthy blood vessels dilate (get larger) to allow more blood to flow through more easily. When you exercise, your heart speeds up so more blood can reach your muscles. It may be possible for your heart rate to double safely, while your blood pressure may respond by only increasing a modest amount.

Heart anatomy

The heart is made of four chambers — two upper chambers (atria) (one is called an atrium) and two lower chambers (ventricles).

The heart also has four valves that open and close to let blood flow in only one direction when the heart contracts (beats). The four heart valves are:

  • Tricuspid valve, located between the right atrium and right ventricle
  • Pulmonary or pulmonic valve, between the right ventricle and the pulmonary artery
  • Mitral valve, between the left atrium and left ventricle
  • Aortic valve, between the left ventricle and the aorta

Each valve has a set of flaps (also called leaflets or cusps). The mitral valve has two flaps; the others have three. Blood flow occurs only when there’s a difference in pressure across the valves, which causes them to open. Under normal conditions, heart valves allow blood to flow in only one direction.

The heart pumps blood to the lungs and to all the body’s tissues by a sequence of highly organized contractions of the four chambers. For the heart to function properly, the four chambers must beat in an organized way.

The heart’s rhythm is normally controlled by a natural pacemaker (the sinus node) in the right upper chamber (right atrium). The sinus node sends electrical signals that normally start each heartbeat. These electrical signals move across the atria, causing the heart muscles to squeeze (contract) and pump blood into the ventricles.

Next, the signals arrive at a cluster of cells called the AV node (atrioventricular node), where they slow down. This slight delay allows the ventricles to fill with blood. When the electrical signals reach the ventricles, the chambers contract and pump blood to the lungs or to the rest of the body.

In a healthy heart, this heart signaling process usually goes smoothly, resulting in a normal resting heart rate of 60 to 100 beats a minute.

Figure 1. The anatomy of the heart

Heart anatomy

Figure 2. The anatomy of the heart chambers

heart chambers

Heart’s Electrical System

To understand arrhythmias, it helps to understand the heart’s internal electrical system. The heart’s electrical system controls the rate and rhythm of the heartbeat (see Figure 3).

Your heartbeat is the contraction of your heart to pump blood to your lungs and the rest of your body. Your heart’s electrical system determines how fast your heart beats. The contraction of the atria and ventricles makes a heartbeat. After your atria pump blood into the ventricles, the valves between the atria and ventricles close to prevent backflow. After your ventricles contract to pump blood away from the heart, the aortic and pulmonary valves close.

Your heart’s electrical system is made up of three main parts:

  • The sinoatrial (SA) node, located in the right atrium of your heart
  • The atrioventricular (AV) node, located on the interatrial septum close to the tricuspid valve
  • The His-Purkinje system, located along the walls of your heart’s ventricles

Each beat of your heart is set in motion by an electrical signal from within your heart muscle. The signal is generated as the vena cavae fill your heart’s right atrium with blood from other parts of your body. The signal spreads across the cells of your heart’s right and left atria. In a normal, healthy heart, each beat begins with a signal from the natural pacemaker called the sinoatrial (SA) node — or sinus node — an area of specialized cells in the right atrium. This is why the sinoatrial (SA) node sometimes is called your heart’s natural pacemaker. Your pulse, or heart rate, is the number of signals the SA node produces per minute. In a healthy adult heart at rest, the SA node sends an electrical signal to begin a new heartbeat 60 to 100 times a minute. (This rate may be slower in very fit athletes.)

The sinoatrial (SA) node produces electrical impulses that normally start each heartbeat. This natural pacemaker produces the electrical impulses that trigger the normal heartbeat. From the sinus node, electrical impulses travel across the atria to the ventricles, causing them to contract and pump blood to your lungs and body.

From the sinoatrial (SA) node, electrical impulses travel across the atria, causing the atrial muscles to contract and pump blood into the ventricles.

The electrical impulses then arrive at a cluster of cells called the atrioventricular (AV) node — usually the only pathway for signals to travel from the atria to the ventricles.

The atrioventricular (AV) node slows down the electrical signal before sending it to the ventricles. This slight delay allows the ventricles to fill with blood.

The signal is released and moves along a pathway called the bundle of His, which is located in the walls of your heart’s ventricles. From the bundle of His, the signal fibers divide into left and right bundle branches through the Purkinje fibers. These fibers connect directly to the cells in the walls of your heart’s left and right ventricles.

The signal spreads across the cells of your ventricle walls, and both ventricles contract. However, this doesn’t happen at exactly the same moment.

The left ventricle contracts an instant before the right ventricle. This pushes blood through the pulmonary valve (for the right ventricle) to your lungs, and through the aortic valve (for the left ventricle) to the rest of your body.

As the signal passes, the walls of the ventricles relax and await the next signal.

This process continues over and over as the atria refill with blood and more electrical signals come from the SA node.

When electrical impulses reach the muscles of the ventricles, they contract, causing them to pump blood either to the lungs or to the rest of your body.

When anything disrupts this complex system, it can cause the heart to beat too fast (tachycardia), too slow (bradycardia) or with an irregular rhythm.

Your heart’s electrical system controls all the events that occur when your heart pumps blood. The electrical system also is called the cardiac conduction system. If you’ve ever seen the heart test called an EKG (electrocardiogram), you’ve seen a graphical picture of the heart’s electrical activity.

Figure 3. The heart’s electrical system

heart's electrical system

Figure 4. The heart’s electrical system

heart's electrical system

Types of arrhythmia

There are many types of arrhythmias, depending on what part of your heart is affected and whether they cause a slow (bradycardia), fast (tachycardia), or irregular heart rate (fibrillation). Arrhythmias may happen in the atria (upper chambers of the heart) or the ventricles (lower chambers of the heart).

Arrhythmias that cause a slow heartbeat

Bradycardia is a resting heart rate that is slower than 60 beats per minute. Bradycardia happens when the electrical impulse that signals the heart to contract is not formed in your heart’s natural pacemaker, the sinoatrial node (SA node), or is not sent to the heart’s lower chambers (the ventricles) through the proper channels.

Some people, especially people who are young or physically fit, may normally have slower heart rates or bradycardia. If you have a slow heart rate, your doctor can find out whether this is normal for you.

However, bradycardia (resting heart rate that is slower than 60 beats per minute) most often affects elderly people. It may be caused by one of two sources: The central nervous system (brain and spinal cord) does not signal that the heart needs to pump more, or the sinus node or sinoatrial (SA) node may be damaged. This damage might be related to heart disease, aging, inherited or congenital defects, or it might be caused by certain medicines—including those used to control arrhythmias and high blood pressure.

Bradycardia can be caused by:

  • Heart tissue damage related to aging
  • Damage to heart tissues from heart disease or heart attack
  • Heart disorder present at birth (congenital heart defect)
  • Infection of heart tissue (myocarditis)
  • A complication of heart surgery
  • Underactive thyroid gland (hypothyroidism)
  • Imbalance of chemicals in the blood, such as potassium or calcium
  • Repeated disruption of breathing during sleep (obstructive sleep apnea)
  • Inflammatory disease, such as rheumatic fever or lupus
  • Medications, including some drugs for other heart rhythm disorders, high blood pressure and psychosis

Arrhythmias that cause a fast heartbeat

Tachycardia is a resting heart rate that is faster than 100 beats per minute. You may also have an irregular heartbeat.

Causes of abnormal tachycardia include:

  • Anemia
  • Drinking too many caffeinated beverages
  • Drinking too much alcohol
  • Exercise
  • Fever
  • High or low blood pressure
  • Other problems with the heart
  • Imbalance of electrolytes, mineral-related substances necessary for conducting electrical impulses
  • Medication side effects
  • Overactive thyroid (hyperthyroidism)
  • Smoking
  • Sudden stress, such as fright
  • Use of stimulant drugs, such as cocaine or methamphetamine

In some cases, the exact cause of tachycardia can’t be determined.

Therefore, if you have a fast heart rate (tachycardia) then you should make an appointment to see your doctor.

Arrhythmias that cause an irregular heartbeat

A premature or extra heartbeat happens when the signal to beat comes too early. This creates a pause, which is followed by a stronger beat when your heart returns to its regular rhythm. It can feel like your heart skipped a beat. This is a common type of arrhythmia, and it can cause other types of arrhythmias.

Ectopic beats

Ectopic beats are a common type of arrhythmia. Many people occasionally have extra or missed beats. Most people don’t notice them.

An increase in ectopic beats can happen because of:

  • anxiety
  • caffeine
  • exertion from exercise
  • nicotine
  • stress
  • tiredness

Supraventricular arrhythmias

Supraventricular arrhythmias occur in the area above the ventricles, usually in the upper chambers of the heart, called the atria. The irregular beats can either be too slow (bradycardia) or too fast (tachycardia).

Atrial fibrillation

Atrial fibrillation or A-fib causes chaotic heart signaling resulting in a rapid, uncoordinated heart rate of more than 400 beats per minute. Also, your heart’s upper and lower chambers do not work together as they should. When this happens, the lower chambers do not fill completely or pump enough blood to your lungs and body. Atrial fibrillation or Afib is the most common type of arrhythmia. More than 2.5 million people in the United States have atrial fibrillation.

Atrial fibrillation or Afib may be temporary, but some A-fib episodes may not stop unless treated. A-fib is associated with serious complications such as cardiac arrest and stroke. People with AFib are 4 to 5 times more likely to have a stroke than those without AFib. So it’s vital to be familiar with stroke symptoms.

Use the letters in F.A.S.T. to spot a stroke

  • F = Face Drooping – Does one side of the face droop or is it numb? Ask the person to smile. Is the person’s smile uneven?
  • A = Arm Weakness – Is one arm weak or numb? Ask the person to raise both arms. Does one arm drift downward?
  • S = Speech Difficulty – Is speech slurred?
  • T = Time to call your local emergency services number for a medical assistance and an ambulance

Other stroke symptoms include:

  • Sudden numbness or weakness of face, arm, or leg, especially on one side of the body
  • Sudden confusion, trouble speaking or understanding speech
  • Sudden trouble seeing in one or both eyes
  • Sudden trouble walking, dizziness, loss of balance or coordination
  • Sudden severe headache with no known cause

Remember to still call your local emergency services number for a medical assistance and an ambulance even if the symptoms are temporary or seem to disappear.

Atrial flutter

Atrial flutter is similar to A-fib, but heartbeats are more organized. Atrial flutter can cause the upper chambers of your heart to beat 250 to 350 times per minute. The signal that tells the atria to beat may be blocked by damaged or scar tissue. This may cause the upper chambers and lower chambers to beat at different rates.

Paroxysmal supraventricular tachycardia (PSVT)

Paroxysmal supraventricular tachycardia (PSVT) causes extra heartbeats because of a problem with the electrical signals that begin in the upper chambers and travel to the lower chambers. This type of arrhythmia begins and ends suddenly. It can happen during vigorous physical activity. It is usually not dangerous and often happens in young people.

Ventricular arrhythmias

Ventricular arrhythmias start in your heart’s lower chambers, called the ventricles. Ventricular arrhythmias can be very dangerous and usually require medical care right away.

Ventricular tachycardia

Ventricular tachycardia is a fast, regular beating of your ventricles that may last for only a few seconds or for much longer. A few beats of ventricular tachycardia often do not cause problems. However, if this lasts for more than a few seconds, it can lead to more serious arrhythmias, such as ventricular fibrillation (v-fib).

Ventricular fibrillation

Ventricular fibrillation occurs if electrical signals make the ventricles quiver instead of pumping normally. Without the ventricles’ pumping blood to the body, cardiac arrest and death can happen within a few minutes.

Atrial fibrillation (A-fib)

Atrial fibrillation also called AFib or AF, is a heart condition that causes an irregular and often abnormally fast heart rate. Atrial fibrillation is a quivering or irregular heartbeat (arrhythmia) that can lead to blood clots, stroke, heart failure and other heart-related complications. During atrial fibrillation, the heart’s two upper chambers (the atria) beat chaotically and irregularly — out of coordination with the two lower chambers (the ventricles) of the heart. When this happens, the lower chambers do not fill completely or pump enough blood to your lungs and body. This can make you feel tired, lightheaded, or dizzy. You may also feel like your heart is skipping a beat, fluttering, pounding, or beating too hard or fast. You may also feel chest pain. Blood may pool in your heart, which increases your risk of forming clots and can lead to strokes or other complications. Atrial fibrillation can also occur without any symptoms, which can make it hard to diagnose. Atrial fibrillation may cause heart disease or worsen existing heart disease. . If left untreated, atrial fibrillation can lead to serious and even life-threatening complications, like stroke or heart failure

Atrial fibrillation is a common supraventricular arrhythmia that is characterized by rapid and irregular activation in the atria without discrete P waves on the surface electrocardiogram (ECG). Atrial fibrillation can be diagnosed with a surface ECG, an intracardiac atrial electrogram, or both. An arrhythmia that has the ECG characteristics of atrial fibrillation and lasts sufficiently long for a 12-lead ECG to be recorded, or is otherwise documented to last for at least 30 seconds, should be considered to be an atrial fibrillation episode 3. The 30-second duration was selected based on previous published consensus statements and is used as the minimal duration to define recurrence of atrial fibrillation after catheter ablation 4. This duration of atrial fibrillation has not been linked to a specific outcome of atrial fibrillation. In addition to the duration requirements listed above, the diagnosis of atrial fibrillation requires an ECG or rhythm strip demonstrating: (1) “absolutely” irregular R-R intervals (in the absence of complete atrioventricular [AV] block); (2) no distinct P waves on the surface ECG; and (3) an atrial cycle length (when visible) that is usually less than 200 ms 5.

Sometimes atrial fibrillation goes away on its own. For some people, atrial fibrillation is an ongoing heart problem that lasts for years. Over time, the irregular heart rhythm may happen more often and each episode may last longer. Your healthcare provider may recommend medicines, medical procedures, and lifestyle changes to treat your atrial fibrillation. Treatment may restore normal heart rhythm, help control your heart rate and symptoms, and prevent complications.

Table 1. Atrial fibrillation definitions

Atrial fibrillation episodeAn atrial fibrillation episode is defined as atrial fibrillation that is documented by ECG monitoring or intracardiac electrogram monitoring and has a duration of at least 30 seconds, or if less than 30 seconds, is present throughout the ECG monitoring tracing. The presence of subsequent episodes of atrial fibrillation requires that sinus rhythm be documented by ECG monitoring between atrial fibrillation episodes.
Chronic atrial fibrillationChronic atrial fibrillation has variable definitions and should not be used to describe populations of atrial fibrillation patients undergoing atrial fibrillation ablation.
Early persistent atrial fibrillationEarly persistent atrial fibrillation is defined as atrial fibrillation that is sustained beyond 7 days but is less than 3 months in duration.
Lone atrial fibrillationLone atrial fibrillation is a historical descriptor that is potentially confusing and should not be used to describe populations of patients with atrial fibrillation undergoing atrial fibrillation ablation.
Long-standing persistent atrial fibrillationLong-standing persistent atrial fibrillation is defined as continuous atrial fibrillation of greater than 12 months’ duration.
Paroxysmal atrial fibrillationParoxysmal atrial fibrillation is defined as atrial fibrillation that terminates spontaneously or with intervention within 7 days of onset.
Permanent atrial fibrillationPermanent atrial fibrillation is defined as the presence of atrial fibrillation that is accepted by the patient and physician, and for which no further attempts to restore or maintain sinus rhythm will be undertaken. The term permanent atrial fibrillation represents a therapeutic attitude on the part of the patient and physician rather than an inherent pathophysiological attribute of atrial fibrillation. The term permanent atrial fibrillation should not be used within the context of a rhythm control strategy with antiarrhythmic drug therapy or atrial fibrillation ablation.
Persistent atrial fibrillationPersistent atrial fibrillation is defined as continuous atrial fibrillation that is sustained beyond 7 days.
Silent atrial fibrillationSilent atrial fibrillation is defined as asymptomatic atrial fibrillation diagnosed with an opportune ECG or rhythm strip.
[Source 3 ]

Figure 5. Atrial fibrillation ECG

atrial fibrillation

Afib symptoms

You may or may not notice atrial fibrillation. It often occurs with no symptoms. If you do have symptoms, you may only notice them occasionally, or your symptoms may be frequent or serious. If you have heart disease, you are more likely to notice symptoms. Symptoms also may increase if your heart disease gets worse. Atrial fibrillation that goes undiagnosed or is left untreated can cause serious and even life-threatening complications, including stroke and heart failure.

The most common symptom of atrial fibrillation is fatigue, or extreme tiredness.

Other atrial fibrillation symptoms include:

  • Low blood pressure
  • Difficulty breathing, especially when lying down or when exercising
  • Chest pain
  • Dizziness or fainting
  • Heart palpitations, or the feeling that your heart is skipping a beat, fluttering, pounding, or beating too hard or too fast

Keep track of when and how often your symptoms occur and what you feel, and note whether these things change over time. They are all important clues to help your healthcare providers diagnose atrial fibrillation.

Atrial tachycardia

Atrial tachycardia is a least common type of supraventricular tachycardia (SVT), constituting 5-15% of all SVTs, that does not require the atrioventricular (AV) junction, accessory pathways, or ventricular tissue for its initiation and maintenance. Atrial tachycardia may occur at any age, although it is more common in children and adults with congenital heart disease. Atrial tachycardia is generally seen in children with underlying heart disorders such as congenital heart disease, particularly those who’ve had heart surgery, particularly after surgery for repair or correction of congenital or valvular heart disease. Atrial tachycardia can also occur in persons with normal hearts.  Atrial tachycardia occurs less commonly with heart attack, serious mitral valve disease. In patients with structurally normal hearts, atrial tachycardia is associated with a low mortality rate. Patients with underlying structural heart disease, congenital heart disease, or lung disease are less likely to be able to tolerate this rhythm disturbance. Atrial tachycardia has no known racial or ethnic predilection and no known predilection for either sex. There may be some association with pregnancy.

Atrial tachycardia may also be triggered by factors such as an infection or drug or alcohol use. For some people, atrial tachycardia increases during pregnancy or exercise.

A normal heart rate is 60 to 100 beats per minute. A heart rate of more than 100 beats per minute is called a tachycardia. This occurs when the electrical impulses that coordinate your heartbeats don’t work properly. It may feel like a fluttering or racing heart.

Atrial tachycardia episodes typically begin slowly, gradually increasing to more than 100 beats per minute before returning to a normal heart rate of around 60 to 80 beats per minute. In some cases, these episodes occur more abruptly or occur continuously. The rapid heartbeat does not allow enough time for your heart to fill before it contracts so blood flow to the rest of your body is compromised.

In adults, tachycardia is usually defined as a heart rate more than 100 beats per minute (bpm). In children, the definition of tachycardia varies because the normal heart rate is age dependent, as follows 6:

  • Age 1-2 days: 123-159 bpm
  • Age 3-6 days: 129-166 bpm
  • Age 1-3 weeks: 107-182 bpm
  • Age 1-2 months: 121-179 bpm
  • Age 3-5 months: 106-186 bpm
  • Age 6-11 months: 109-169 bpm
  • Age 1-2 years: 89-151 bpm
  • Age 3-4 years: 73-137 bpm
  • Age 5-7 years: 65-133 bpm
  • Age 8-11 years: 62-130 bpm
  • Age 12-15 years: 60-119 bpm

Heartbeats are normally initiated by a small group of cells at the top of the heart in the right atrium called the sinoatrial node (SA node), which acts as the heart’s natural pacemaker (see Figure 1).

The sinoatrial node (SA node) produces electrical signals that pass through the muscles of the upper heart chambers (atria), causing them to contract and pump blood into the lower heart chambers (ventricles).

The signal then passes into another group of cells in the middle of the heart called the atrioventricular (AV) node. From here, the signals travel into the ventricle muscles, causing them to contract and pump blood out of the heart.

Episodes of atrial tachycardia or supraventricular tachycardia (SVT) occur when a problem develops in the heart’s electrical system. This causes faster signals to be sent around the heart, increasing the speed at which the heart beats.

A number of methods are used to classify atrial tachycardia. Classification in terms of origin can be based on endocardial activation mapping data, pathophysiologic mechanisms, and anatomy.

On the basis of endocardial activation, atrial tachycardia may be divided into the following 2 groups:

  • Focal atrial tachycardia: Arises from a localized area in the atria such as the crista terminalis, pulmonary veins, ostium of the coronary sinus, or intra-atrial septum. If it originates from the pulmonary veins, it may trigger atrial fibrillation and often forms a continuum of arrhythmias.
  • Reentrant atrial tachycardias: Usually macroreentrant; reentrant atrial tachycardias most commonly occur in persons with either structural or complex heart disease, particularly after surgery involving atrial incisions or scarring. Electrophysiologically, these atrial tachycardias are similar to atrial flutters, typical or atypical. Often, the distinction is semantic, typically based on arbitrary cutoffs of atrial rate.
  • Other methods of classification are as follows:
    • Pathophysiologic mechanisms: Atrial tachycardia can be classified as the result of enhanced automaticity, triggered activity, or reentry
    • Anatomy: Classification of atrial tachycardia can be based on the location of the arrhythmogenic focus.

Atrial tachycardia can have a right or left atrial origin. Some atrial tachycardias actually originate outside the usual anatomic boundaries of the atria, in areas such as the superior vena cava, pulmonary veins, and vein of Marshall, where fingers of atrial myocardium extend into these locations. Rare locations, such as the noncoronary aortic cusp 7 and hepatic veins, have been described, as well.

A number of aspects of the atrial anatomy can contribute to the substrate for arrhythmia. The orifices of the vena cava, pulmonary veins, coronary sinus, atrial septum, and mitral and tricuspid annuli are potential anatomic boundaries for reentrant circuits.

Anisotropic conduction in the atria due to complex fiber orientation may create the zone of slow conduction. Certain atrial tissues, such as the crista terminalis and pulmonary veins, are common sites for automaticity or triggered activity. Additionally, disease processes or age-related degeneration of the atria may give rise to the arrhythmogenic substrate.

  • Abnormalities that have been reported at the sites of atrial tachycardia origin include the following 8 :
  • Extensive myocardial fibrosis
  • Myocyte hypertrophy
  • Endocardial fibrosis
  • Mononuclear cell infiltration
  • Mesenchymal cell proliferation
  • Islets of fatty tissue
  • Thinning
  • Blebs

Manifestations of atrial tachycardia include the following:

  • Rapid pulse rate: In most atrial tachycardias, the rapid pulse is regular; it may be irregular in rapid atrial tachycardias with variable AV conduction and in multifocal atrial tachycardia (multifocal atrial tachycardia)
  • Episodic or paroxysmal occurrence
  • Sudden onset of palpitations
  • Continuous, sustained, or repetitive tachycardia: If atrial tachycardia is due to enhanced automaticity
  • Warm-up phenomenon: Tachycardia gradually speeds up soon after onset (may be clinically inapparent)
  • Dyspnea, dizziness, lightheadedness, fatigue, or chest pressure: In tachycardic episodes accompanied by palpitations
  • Syncope: With rapid rate and severe hypotension
  • Heart-failure symptoms and reduced effort tolerance: Early manifestations of tachycardia-induced cardiomyopathy in patients with frequent or incessant tachycardia

Figure 6. Atrial tachycardia ECG

Atrial tachycardia ECG

Atrial tachycardia symptoms

Some people have no symptoms; others may feel:

  • Fainting (syncope)
  • Lightheadedness or dizziness
  • Rapid heartbeat or “palpitations” or fluttering feeling in chest or bounding pulse
  • Angina (chest pain), pressure or tightness
  • Shortness of breath
  • Fatigue/tiredness

In extreme cases, atrial tachycardia or SVT may cause:

  • Unconsciousness
  • Cardiac arrest

In patients with multifocal atrial tachycardia, the history may disclose an underlying illness that is causing the tachycardia. Such illnesses include pulmonary, cardiac, metabolic, and endocrinopathic disorders. Chronic obstructive pulmonary disease (COPD) is the most common underlying disease process (60%) in multifocal atrial tachycardia.

Reentrant atrial tachycardia is not uncommon in patients with a history of a surgically repaired atrial septal defect. The scar tissue in the atrium may give rise to the formation of a reentrant circuit.

On physical examination, the primary abnormal finding is a rapid pulse rate. The rate is usually regular, but it may be irregular in rapid atrial tachycardias with variable AV conduction and in multifocal atrial tachycardia. Blood pressure may be low in patients presenting with fatigue, lightheadedness, or presyncope.

Atrial flutter

Atrial flutter is an abnormal heart rhythm (arrhythmia) that occurs in the atria of the heart, which can cause your heart to beat much faster than they should, around 300 beats per minute instead of the usual 60-90 beats per minute, but in a regular pattern. When atrial flutter first occurs, it is usually associated with a fast heart rate or tachycardia (beats over 100 per minute), and falls into the category of supra-ventricular tachycardias (SVTs). While this rhythm occurs most often in individuals with cardiovascular disease (e.g. hypertension, coronary artery disease, and cardiomyopathy) and diabetes mellitus, atrial flutter may occur spontaneously in people with otherwise normal hearts. Atrial flutter is typically not a stable rhythm, and frequently degenerates into atrial fibrillation (AF). Some people with atrial flutter also have atrial fibrillation and may experience periods of atrial flutter followed by periods of atrial fibrillation. However, atrial flutter does rarely persist for months to years.

Atrial flutter is a heart rhythm disorder that is similar to the more common atrial fibrillation (AF). In atrial fibrillation (AF), the heart beats fast and in irregular pattern or rhythm. With atrial flutter, the heart beats abnormally fast, but in a regular pattern. The fast, but regular pattern of atrial flutter is what makes it special. Atrial flutter makes a very distinct “sawtooth” pattern on an electrocardiogram (ECG or EKG), a test used to diagnose abnormal heart rhythms.

A normal heartbeat begins as a single electrical impulse that comes from the sinoatrial (SA) node, a small bundle of tissue located in the right atrium (see Figure 3). The impulse sends out an electrical pulse that causes the atria to contract (squeeze) and move blood into the lower ventricles. The electrical current passes through the atrioventricular (AV) node (the electrical bridge between the upper and lower chambers of the heart), causing the ventricles to squeeze and release in a steady, rhythmic sequence. As the chambers squeeze and release, they draw blood into the heart and push it back out to the rest of the body and lungs. This is what causes the pulse we feel on our wrist or neck.

If you have atrial flutter, the electrical impulses that tell your heart when to beat form a smaller circuit (it moves in an organized abnormal circular motion) in the top chambers of your heart (your atria), instead of traveling from your heart’s sinoatrial (SA) node to the AV (atrioventricular) node as they should. These impulses circulate very fast around your atria, causing your atria to beat much faster than they should, around 300 beats per minute instead of the usual 60-90 beats per minute. The bottom chambers of your heart (your ventricles) can’t pump this fast, so they will usually beat between 75 and 150 beats per minute. Your atria and ventricles will be beating at different speeds, putting your heart under strain. Atrial flutter can also cause blood to pool in your ventricles which can lead to a blood clot forming in your heart. If the clot breaks off, it could cause a stroke, so it’s important that you receive the right treatment for your atrial flutter.

Atrial flutter is much less common than atrial fibrillation. Of the patients admitted to US hospitals with a diagnosis of supraventricular tachycardia (SVT) between 1985 and 1990, 77% had atrial fibrillation and 10% had atrial flutter. On the basis of a study of patients referred to tertiary care centers, the incidence of atrial flutter in the United States is estimated to be approximately 200,000 new cases per year 9.

In a study of 100 patients with atrial flutter, 75% were men. In another study performed at a tertiary care study, atrial flutter was 2.5 times more common in men.

Patients with atrial flutter, as with atrial fibrillation, tend to be older adults. In one study, the average age was 64 years. The prevalence of atrial fibrillation increases with age, as follows:

  • 25-35 years: 2-3 cases per 1000 population
  • 55-64 years: 30-90 cases per 1000 population
  • 65-90 years: 50-90 cases per 1000 population

Figure 7. Atrial flutter ECG (atrial flutter EKG) – note the “sawtooth pattern”

Atrial flutter ECG

Atrial flutter symptoms

Although people with atrial flutter often have no symptoms, symptoms can include:

  • palpitations
  • shortness of breath
  • fatigue
  • feeling light-headed
  • fainting
  • tightness in your chest

If you’re experiencing any of these symptoms, especially if you already have a heart condition, speak to your doctor.

Premature ventricular contractions

Premature ventricular contractions are extra heartbeats that is initiated by Purkinje fibers, an ectopic cardiac pacemaker located in the ventricles rather than by the sinoatrial node, the normal heartbeat initiator. These extra beats disrupt your regular heart rhythm, sometimes causing you to feel a fluttering or a “skipped beat” or felt as palpitations in your chest. The electrical events of the heart detected by the electrocardiogram (ECG) allow a premature ventricular contraction to be easily distinguished from a normal heart beat (see Figure 1 premature ventricular contractions ECG below). Although a premature ventricular contraction can be a sign of decreased oxygenation to the heart muscle, often premature ventricular contractions are benign and may even be found in otherwise healthy hearts.

In a normal heartbeat, the ventricles contract after the atria have helped to fill them by contracting; in this way the ventricles can pump a maximized amount of blood both to the lungs and to the rest of the body. In a premature ventricular contraction, the ventricles contract first and before the atria have optimally filled the ventricles with blood, which means that circulation is inefficient. However, single beat premature ventricular contraction abnormal heart rhythms do not usually pose a danger and can be asymptomatic in healthy individuals. A premature ventricular contraction is a type of ectopic heartbeat.

Premature ventricular contractions are characterized by premature and bizarrely shaped QRS complexes that are unusually long (typically >120 msec) and appear wide on the electrocardiogram (ECG). These complexes are not preceded by a P wave, and the T wave is usually large and oriented in a direction opposite the major deflection of the QRS. The clinical significance of premature ventricular contractions depends on their frequency, complexity, and hemodynamic response.

Premature ventricular contractions often cause few or no symptoms. But you might feel an odd sensation in your chest, such as:

  • Fluttering
  • Pounding or jumping
  • Skipped beats or missed beats
  • Increased awareness of your heartbeat

Premature ventricular contractions are one of the most common arrhythmias and can occur in patients with or without heart disease. Their prevalence varies greatly, with estimates ranging from less than 3% to more than 60% in asymptomatic individuals. Data from large, population-based studies indicate that the prevalence ranges from less than 3% for young white women without heart disease to almost 20% for older African American individuals with hypertension.

Black race is associated with an increased frequency of premature ventricular contractions on routine monitoring 10. In a large population-based study of premature ventricular contraction prevalence, black race alone increased the risk of premature ventricular contractions by 30% in comparison with the risk in white individuals.

Ventricular ectopy is more prevalent in men than in women of the same age. Male sex alone increases the risk of identifying premature ventricular contractions on routine screening, with an odds ratio for male sex of 1.39 as compared with female sex.

Premature ventricular contraction frequency increases with age, reflecting the increased prevalence of hypertension and cardiac disease in aging populations.

Premature ventricular contractions are also called:

  • Premature ventricular complexes
  • Ventricular premature beats
  • Ventricular extrasystoles

If you have occasional premature ventricular contractions, but you’re otherwise healthy, there’s probably no reason for concern, and no need for treatment. If you have frequent premature ventricular contractions or underlying heart disease, you might need treatment.

Figure 8. Premature ventricular contraction ECG

Premature ventricular contraction ECG

Premature ventricular contractions symptoms

Premature ventricular contractions often cause few or no symptoms. But you might feel an odd sensation in your chest, such as:

  • Fluttering
  • Pounding or jumping
  • Skipped beats or missed beats
  • Increased awareness of your heartbeat

Wolff-Parkinson-White Syndrome

Wolff-Parkinson-White syndrome also known as WPW syndrome, accessory atrioventricular pathways or preexcitation syndrome, is a heart condition that causes the heart to beat abnormally fast for periods of time 11.

Wolff-Parkinson-White syndrome is caused by an abnormal electrical pathways between the atria and ventricles (called accessory pathways) causing the electrical signal to arrive at the ventricles too soon and to be transmitted back into the atria. These accessory pathways can cause electrical impulses to travel in both directions rather than one direction (normal direction from the atria into the ventricles). In Wolff-Parkinson-White (WPW) syndrome, an extra electrical pathway between your heart’s upper chambers and lower chambers causes a rapid heartbeat. Some people with Wolff Parkinson White syndrome also have atrial fibrillation. Wolff Parkinson White syndrome causes the conduct of impulses to be faster than normal. Very fast heart rates may develop as the electrical signal ricochets between the atria and ventricles. Some people with WPW syndrome don’t have symptoms but they still have an increased risk for sudden cardiac death. The cause of sudden cardiac death in WPW syndrome is rapid conduction of atrial fibrillation (AF) to the ventricles via the accessory pathway, resulting in ventricular fibrillation (VF) 12, 11. The incidence of sudden cardiac death in WPW syndrome is approximately 1 in 100 symptomatic cases when followed for up to 15 years 12. Although relatively uncommon, sudden cardiac death may be the initial presentation in as many as 4.5% of cases 12.

Wolff-Parkinson-White (WPW) syndrome heart problem is present at birth (congenital), although symptoms may not develop until later in life. Many cases are diagnosed in otherwise healthy adults aged between 20 and 40.

The most common sign of Wolff-Parkinson-White syndrome is a heart rate greater than 100 beats a minute (tachycardia) 13. Episodes of a fast heart rate (tachycardia) can begin suddenly and may last a few seconds or several hours. Episodes can occur during exercise or while at rest. They most often appear for the first time in people in their teens or 20s.

Patients with WPW syndrome may also experience palpitations, dizziness, syncope (fainting), congestive heart failure or sudden cardiac death 14.

Sometimes the extra electrical connection won’t cause any symptoms and may only be picked up when an electrocardiogram (ECG) test is carried out for another reason. This condition is called Wolff-Parkinson-White pattern (WPW pattern). In these cases, further tests will be done to determine if treatment is required.

Doctors can detect WPW syndrome through a routine exam known as an electrocardiogram or ECG (see Figures 2 to 4). Electrodes placed on the chest will pick up the heart’s electrical activity and chart it on a graph. The electrocardiogram or ECG will show any irregularities.

The ECG features of WPW include a short PR interval of <0.12 seconds, slurring and slow rise of the initial QRS complex (delta wave), a widened QRS complex with a total duration >0.12 seconds, and an abnormal ventricular repolarization 11.

Treatment of WPW syndrome may include special actions, medications, a shock to the heart (cardioversion) or a catheter procedure to stop the irregular heart rhythm (arrhythmia).

Figure 9. Wolff Parkinson White syndrome

WPW syndrome
Footnote: In Wolff-Parkinson-White (WPW) syndrome, an extra electrical pathway between your heart’s upper chambers and lower chambers causes a rapid heartbeat.

Wolff Parkinson White syndrome symptoms

If you have WPW syndrome, you may not have any symptoms of an arrhythmia. If you do have symptoms, you may notice that they change over time. For example, you may develop symptoms, or your symptoms may go away, as you get older. Sometimes the first sign of WPW syndrome is a life-threatening arrhythmia or sudden cardiac arrest.

Wolff Parkinson White syndrome symptoms may include:

  • Palpitations, or feeling your heart beat fast
  • Chest pain or tightness
  • Shortness of breath
  • Dizziness and fainting

Ventricular tachycardia (V-tach)

Ventricular tachycardia also be called V-tach or VT, is a fast abnormal heart rhythm disorder (arrhythmia) that starts in the lower chambers of your heart (ventricles), the abnormal electrical signals in the ventricles cause the heart to beat faster than normal, usually 100 or more beats a minute that is out of sync with the upper chambers 15. Some experts define ventricular tachycardia as ≥ 3 consecutive ventricular beats at a rate ≥ 120 beats/min 16. Other experts use a cutoff rate of ≥ 100 beats/min with at least 3 irregular heartbeats in a row for ventricular tachycardia 17.

A healthy heart normally beats about 60 to 100 times a minute when at rest and is defined by signals that originate in the upper chambers of the heart (atria).

In ventricular tachycardia, abnormal electrical signals in the ventricles cause the heart to beat faster than normal, usually 100 or more beats a minute, out of sync with the upper chambers. When that happens, your heart may not be able to pump enough blood to your body and lungs because the chambers are beating so fast or out of sync with each other that they don’t have time to fill properly.

Ventricular tachycardia may be brief, lasting for only a few seconds, and perhaps not cause any symptoms. Or it can last for much longer and cause symptoms such as dizziness, lightheadedness, palpitations or even loss of consciousness. Episodes that last for more than a few seconds can be dangerous. Ventricular tachycardia can turn into other more serious arrhythmias, such as ventricular fibrillation (VF).

In some cases, ventricular tachycardia can cause your heart to stop (sudden cardiac arrest), which is a life-threatening medical emergency. This condition usually occurs in people with other heart conditions, such as those who have had a previous heart attack or other structural heart disease (cardiomyopathy).

The outcome of ventricular tachycardia depends on the heart condition and symptoms.

Among patients younger than 35 years, the most common cardiac causes of sudden death, and presumably of ventricular tachycardia, include the following 18:

  • Hypertrophic cardiomyopathy
  • Right ventricular cardiomyopathy (arrhythmogenic right ventricular dysplasia)
  • Myocarditis
  • Long QT syndrome
  • Congenital coronary artery abnormalities

Ventricular tachycardia is unusual in children but may occur in the postoperative cardiac setting or in patients with associated congenital heart disease. Tachydysrhythmias in children are more commonly due to paroxysmal supraventricular tachycardias (PSVTs) 19. The incidence of ischemic ventricular tachycardia increases with age, regardless of sex, as the prevalence of coronary artery disease increases. Ventricular tachycardia rates peak in the middle decades of life, in concert with the incidence of structural heart disease. Idiopathic ventricular tachycardia can be observed at any age.

Ventricular tachycardia can be classified as sustained or nonsustained, with a generally accepted cutoff of 30 seconds.

Ventricular tachycardia is further classified according to the electrocardiographic (ECG) appearance. If the QRS complex remains identical from beat to beat, as occurs when ventricular tachycardia originates from a single focus or circuit, it is classified as monomorphic (Figure 1 below). Monomorphic ventricular tachycardia means that the appearance of all the heart beats match each other in each lead of a surface electrocardiogram (ECG). Scar-related monomorphic ventricular tachycardia is the most common type and a frequent cause of death in patients having survived a heart attack or myocardial infarction, especially if they have weak heart muscle.

If the QRS morphology changes from beat to beat, the ventricular tachycardia is classified as polymorphic ventricular tachycardia (Figure 2 below). Further classification can be made on the basis of the substrate and the location of the earliest activation.

Figure 10. Ventricular tachycardia ECG

ventricular tachycardia

Ventricular tachycardia symptoms

Ventricular tachycardia may not cause symptoms in some people. However, ventricular tachycardia can be deadly, especially after degeneration to ventricular fibrillation (VF) 20. Patients in whom this occurs may first present with syncope (fainting). Ventricular tachycardia is a major cause of sudden cardiac death.

You may have symptoms if the heart rate during a ventricular tachycardia episode is very fast or lasts longer than a few seconds. Symptoms may include:

  • Chest discomfort (angina)
  • Fainting (syncope)
  • Lightheadedness or dizziness
  • Sensation of feeling the heart beat (palpitations)
  • Shortness of breath

Symptoms may start and stop suddenly. In some cases, there are no symptoms.

During ventricular tachycardia, the following may be observed:

  • Hypotension (low blood pressure)
  • Tachypnea (abnormally rapid breathing)
  • Signs of diminished perfusion, including a diminished level of consciousness, pallor, and diaphoresis
  • High jugular venous pressure
  • Cannon A waves (if the atria are in sinus rhythm)
  • Variation in intensity of first heart sound (S1), caused by loss of atrioventricular (AV) synchrony

After cardioversion, physical findings during normal sinus rhythm are related to any underlying structural heart disease.

Heart block

Heart block is a condition where your heart beats more slowly or with an abnormal rhythm (arrhythmia). Heart block is a problem that occurs with your heart’s electrical system. Your heart’s electrical system controls the rate and rhythm of heartbeats. “Rate” refers to the number of times your heart beats per minute. “Rhythm” refers to the pattern of regular or irregular pulses produced as the heart beats.

With each heartbeat, an electrical signal spreads across the heart from the upper chambers (atria) to the lower chambers (ventricles). As the heart electrical signal travels, the signal causes the heart to contract and pump blood. In cases of heart block, the electrical signals that progress from the heart’s upper chambers (atria) to its lower chambers (ventricles) are impaired. When those signals don’t transmit properly, the heart beats irregularly.

Heart block occurs if the electrical signal is slowed or disrupted as it moves through the heart.

There are three main types of heart block:

  1. AV (atrioventricular) heart blocks
  2. Bundle branch blocks
  3. Tachybrady syndrome

Some people are born with heart block – known as congenital heart block.

But more commonly, heart block develops later in life. This is known as acquired heart block and can be caused by:

  • heart surgery – thought to be one of the most common causes of complete heart block
  • being an athlete – some athletes get first-degree heart block because their hearts are often bigger than normal, which can slightly disrupt their heart’s electrical signals
  • a history of coronary heart disease, heart attack or heart failure – this can leave the heart tissues damaged
  • some diseases – such as myocarditis, cardiomyopathy, Lyme disease, sarcoidosis, Lev’s disease, diphtheria or rheumatic fever
  • exposure to some toxic substances
  • low levels of potassium (hypokalaemia) or low magnesium (hypomagnesemia) in the blood
  • high blood pressure (hypertension) that isn’t well controlled
  • cancer that’s spread from another part of the body to the heart
  • a penetrating trauma to the chest – such as a stab wound or gunshot wound

Certain medications can also cause first-degree heart block, including:

  • medication for abnormal heart rhythms – such as disopyramide
  • medications for high blood pressure – such as beta blockers, calcium channel blockers, or clonidine
  • digoxin – a medication used to treat heart failure
  • fingolimod – used for treating certain types of multiple sclerosis
  • pentamidine – used to treat some types of pneumonia
  • tricyclic antidepressants – such as amitriptyline

Figure 11. Heart block ECG

Heart block ECG

AV (atrioventricular) heart blocks

An AV heart block happens when the electrical impulses are delayed or blocked as they travel between your atria (the top chambers of your heart) and your ventricles (the bottom chambers of your heart).

There are three ‘degrees’ of AV heart block:

  1. First-degree heart block, which usually doesn’t cause symptoms or need treatment
  2. Second-degree heart block
  3. Third-degree (complete) heart block

AV heart block can be caused by coronary heart disease, congenital heart disease, cardiomyopathy, ageing of the electrical pathways in your heart, and some medicines. The type of treatment you’ll need will depend on the cause and symptoms. Some AV heart blocks may develop into higher degree AV heart blocks if they’re left untreated. Your doctor will be able to give you advice about this.

Some people always have AV heart block but in others the condition can come and go.

First degree heart block

First-degree degree heart block or 1st degree atrioventricular (AV) block is defined as a PR interval of greater than 0.20 seconds on electrocardiography (ECG) without disruption of atrial to ventricular conduction (Figure 2) 21. First-degree degree heart block may cause dizziness or lightheadedness, or it may cause no symptoms at all and without significant complications. For the vast majority of patients, first-degree heart block may not require specific treatment beyond routine observation for worsening conduction delay. Regular evaluation is important, however, as affected patients have been shown to have an increased risk of developing atrial fibrillation (A Fib) or higher-degree atrioventricular (AV) block 22.

First-degree heart block occurs when the electrical impulse moves through the heart’s atrioventricular (AV) node more slowly than normal. This usually results in a slower heart rate.

Certain medications can cause first-degree heart block as a side effect:

  • Digitalis: This medication is commonly used to slow down the heart rate. If it’s taken in high dosages or for a long period, digitalis can cause first-degree heart block.
  • Beta blockers: These drugs inhibit the part of the nervous system that speeds up the heart. This can have the side effect of delaying electrical conduction within the heart, which can cause first-degree heart block.
  • Calcium channel blockers: Among their other effects, calcium channel blockers can slow down the conduction within the heart’s AV node, resulting in first-degree heart block.

If you have first-degree heart block, it’s important to check in regularly with your doctor to monitor the condition. Between appointments with the doctor, you should take your pulse regularly and watch out for slower than normal heart rates.

Figure 12. 1st degree heart block

First degree heart block

Footnote: EKG, cardiac complex noting a significantly prolonged PR interval (0.28 seconds) consistent with first degree heart block.

Second degree heart block

Second-degree heart block occurs when electrical signals from the heart’s upper chambers (atria) don’t reach the lower chambers (ventricles). This can result in “dropped beats.”

Symptoms of 2nd degree heart block include:

  • Chest pain
  • Fainting (syncope)
  • Heart palpitations
  • Breathing difficulties, such as shortness of breath (during exertion)
  • Rapid breathing
  • Nausea
  • Excessive fatigue

There are two types of second-degree heart blocks: Mobitz type I, also known as, Wenckebach and Mobitz type II 23.

2nd degree heart block type 1

Mobitz type 1 (Wenckebach block) is often a normal variant and seen in individuals with a high vagal tone without evidence of structural heart disease. However, this rhythm can result from inferior myocardial ischemia, medication toxicity (AV nodal blocking agents), hyperkalemia, cardiomyopathy (Lyme disease), or following cardiac surgery.

In Mobitz type 1 (Wenckebach block) there is a progressive prolongation of the PR interval (AV conduction) until eventually an atrial impulse is completely blocked 23. When an atrial impulse is completely blocked there will be a P wave without a QRS complex. This pattern is often referred to as a “dropped beat.” Mobitz type 1 (Wenckebach block) occurs because each depolarization results in the prolongation of the refractory period of the atrioventricular (AV) node. When an atrial impulse comes through the AV node during the relative refractory period, the impulse will be conducted more slowly, resulting in a prolongation of the PR interval. Eventually, an impulse comes when the AV node is in its absolute refractory period and will not be conducted. This will manifest on the ECG as a P wave that is not followed by a QRS complex. This non-conducted impulse allows time for the AV node to reset, and the cycle continues. This phenomenon leads to a grouped beating.

Mobitz type 1 (Wenckebach block) may not cause noticeable symptoms. Still, it can be a forerunner for the more serious type of second-degree heart block, Mobitz type 2. For this reason, Mobitz Type 1 should be monitored carefully by your doctor. Daily pulse checks on your own may also be advised.

Common drugs that are known to cause second-degree heart block include beta blockers, digoxin, calcium channel blockers and many antiarrhythmic agents. Recently the immunosuppressant agent, fingolimod, used to treat relapsing multiple sclerosis was also found to cause second-degree heart block 23.

Figure 13. Second degree heart block type 1

Second degree heart block type 1

2nd degree heart block type 2

In this second-degree heart block Mobitz type 2, the heart doesn’t beat effectively. It impacts the heart’s ability to pump blood throughout the body. Often, a pacemaker is necessary to ensure that the heart will continue to beat regularly and efficiently.

Mobitz type 2 is rarely seen in patients without structural heart disease. It is often associated with myocardial ischemia and fibrosis or sclerosis of the myocardium. This rhythm often progresses to third-degree heart block (complete heart block).

In Mobitz type 2 there is a constant PR interval across the rhythm strip both before and after the non-conducted atrial beat. Each P wave is associated with a QRS complex until there is one atrial conduction or P wave that is not followed by a QRS. Mobitz type 2 is often a problem in the infra-nodal conduction system, and therefore, is associated with a widened QRS complex, bundle-branch block, or fascicular block. Be aware that if more than one P wave is not conducted this is no longer a Mobitz type 2 and is considered a high degree AV block.

Figure 14. Second degree heart block type 2

Second degree heart block type 2

Third degree heart block

Third-degree heart block or complete heart block (sometimes called third-degree AV heart block) means that electrical signals can’t pass at all from the heart’s upper chambers (atria) to its lower chambers (ventricles). In the absence of electrical impulses from the sinoatrial node, the ventricles will still contract and pump blood, but at a slower rate than usual. This can affect the flow of blood to your body and brain.

Complete heart block is the most serious type of AV heart block. With third-degree heart block, the heart does not contract properly, and it can’t pump blood out to the body effectively.

Symptoms for third-degree heart block include:

  • Chest pain
  • Fainting (syncope)
  • Dizziness
  • Excessive fatigue
  • Shortness of breath

Complete heart block may also cause fluid to build up in your body.

In some people, complete heart block is always there, while in others it comes and goes.

Figure 15. Third-degree heart block or complete heart block (sometimes called third-degree AV heart block) 

third-degree AV heart block

Bundle branch blocks

Bundle branch blocks happen when the electrical impulses travel through the bottom chambers of your heart (your ventricles) more slowly than normal because of a block in the electrical pathway. Bundle branch blocks will always cause symptoms and could be a sign of an underlying heart condition which you might need treatment for.

There are two types of bundle branch blocks:

Left bundle branch block

Left bundle branch block (LBBB) is usually caused by an underlying condition such as coronary heart disease, cardiomyopathy, thickening of the heart muscle (left ventricular hypertrophic cardiomyopathy) or ageing of the electrical pathway in your heart.

Right bundle branch blocks

Right bundle branch block (RBBB) can be caused by coronary heart disease, congenital heart disease, or some lung conditions. However it can also happen naturally in people with a normal heart and no heart problems.

Tachybrady syndrome

Tachybrady syndrome happens when your heart’s sinus node doesn’t work properly. Your sinus node (sometimes called your heart’s natural pacemaker) is responsible for telling your heart when to beat. If your sinus node doesn’t work properly, it can cause your heartbeat to become too fast or too slow, or switch between fast and slow rhythms. An example of this is when atrial flutter (a fast heart rhythm) alternates with a slow heart rhythm.

There might also be sudden pauses in the electrical activity in your heart, which could lead to you feeling dizzy, lightheaded, or sometimes collapsing.

The most likely cause of tachybrady syndrome is ageing of the electrical pathway in your heart but it can also be caused by coronary heart disease, for example after a heart attack, and some medicines. If you have tachybrady syndrome you might need a combination of medicines or have a pacemaker fitted.

Heart block symptoms

First-degree heart block

First-degree heart block doesn’t usually cause any noticeable symptoms. Most people only find out they have it when they’re tested for an unrelated medical condition.

Second-degree heart block

Most people with the less serious type of second-degree heart block, known as Mobitz type 1, won’t experience any symptoms.

But some people may experience:

  • mild light-headedness or dizziness
  • fainting

People with the more serious type of second-degree heart block, known as Mobitz type 2 heart block, are more likely to experience the above symptoms.

They may also experience:

  • chest pain
  • shortness of breath
  • feeling very dizzy suddenly when standing up from a lying or sitting position – this is caused by having low blood pressure (hypotension)

Third-degree heart block

Symptoms of third-degree or complete heart block include:

  • fainting – this can cause someone to collapse
  • breathlessness
  • extreme tiredness (fatigue), sometimes with confusion
  • chest pain
  • having a slow heart beat (bradycardia), or feeling a skipping, fluttering or pounding in your chest (palpitations)

If you experience severe symptoms or ones that come on very quickly, dial your local emergency services number to request an ambulance. These symptoms can be life threatening.

All types of heart block can increase your risk of developing other types of heart rhythm problems, such as atrial fibrillation (an irregular and abnormally fast heart rate).

Arrhythmia causes

Arrhythmias are often caused by a problem with the electrical signals within your heart. Often, an arrhythmia is set off by a trigger. Sometimes the cause of an arrhythmia is not known.

Your heart’s electrical signals control how fast your heart beats. A problem with these electrical signals can cause an irregular rhythm. This can happen when the nerve cells that produce electrical signals do not work properly or when the electrical signals do not travel normally through your heart. Also, another part of your heart could start to produce electrical signals, disrupting your normal heartbeat.

Conditions that cause a slowing of your heart’s electrical signals are called conduction disorders.

Arrhythmias can be caused by:

  • A delay or blockage of the electrical signals that control the heartbeat.
  • Another part of the heart taking over as pacemaker.
  • Changes to heart tissue cause by changes in blood flow, damage to the heart’s electrical system or stiffening or scarring of the heart tissue.
  • Current heart attack or scarring from a previous heart attack.
  • Blocked arteries in the heart (coronary artery disease).
  • Changes to the heart’s structure, such as from cardiomyopathy
  • Excessive exertion, strain or stress.
  • Anxiety.
  • An imbalance of fluids, hormones or electrolytes in the blood.
  • Certain heart medications.
  • Diabetes
  • High blood pressure
  • Overactive thyroid gland (hyperthyroidism)
  • Underactive thyroid gland (hypothyroidism)
  • Certain medications, including cold and allergy drugs bought without a prescription
  • Drinking too much alcohol or caffeine
  • Drug abuse
  • Genetics
  • Smoking
  • Sleep apnea
  • Infection with COVID-19

Risk factors for arrhythmia

Risk factors that may increase the risk of heart arrhythmias include:

  • Coronary artery disease, other heart problems and previous heart surgery. Some types of heart disease, such as narrowed heart arteries, a heart attack, abnormal heart valves, prior heart surgery, heart failure, cardiomyopathy, other heart damage, are risk factors for almost any kind of arrhythmia including AFib
  • Age. The prevalence of arrhythmia and AFib increases with age. As you age, changes in your heart such as scarring and the effects of other chronic conditions can raise your risk of arrhythmias. Growing older also increases your risk of damaged and narrowed arteries and a weakened or thickened heart muscle. Older adults are also more likely to have health conditions, such as high blood pressure, heart failure, diabetes, and thyroid disease, that can lead to arrhythmias. Genetics or lifestyle factors cause plaque to build up in your arteries as you age. In men, the risk for coronary heart disease increases starting at age 45. In women, the risk for coronary heart disease increases starting at age 55. About 83% of people who die from heart disease are 65 or older.
  • Congenital heart disease. Being born with a heart condition may make a person prone to arrhythmia. For example, a congenital heart defect that affects the heart’s built-in electrical system can cause bradycardia. And those born with extra electrical pathways can be prone to tachycardia.
  • Thyroid disease. Having an overactive thyroid gland or underactive thyroid gland can raise the risk of irregular heartbeats.
  • Chemical agents. Different kinds of chemical agents can cause arrhythmias, sometimes with serious consequences. Minerals such as potassium, magnesium and calcium play a vital role in the heart’s normal function. But those same minerals may cause arrhythmias when their levels are too high or too low. Addictive substances, including alcohol, cigarettes and recreational drugs, can also provoke arrhythmias. Even various cardiac medications may cause arrhythmia.
  • Lifestyle habits. Certain lifestyle habits including drinking alcohol, smoking cigarettes and using illegal drugs, such as cocaine and amphetamines, can also cause arrhythmias.
  • Medications. Some prescription drugs and certain cough and cold medications bought without a prescription can cause arrhythmias.
  • High blood cholesterol (hypercholesterolemia). High levels of cholesterol in your blood can increase the risk of plaque formation and atherosclerosis.
  • High blood pressure (hypertension). High blood pressure increases your risk of developing coronary artery disease. It may also cause the walls of the left lower heart chamber (left ventricle) to become stiff and thick, which can change how electrical signals travel through the heart. Furthermore, uncontrolled high blood pressure can result in hardening and thickening of your arteries too, narrowing the blood vessels through which blood flows. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)
  • Diabetes. Diabetes increases your risk of heart disease. Both conditions share similar risk factors, such as obesity and high blood pressure.
  • Insulin resistance. This condition occurs if the body can’t use its own insulin properly. Insulin is a hormone that helps move blood sugar into cells where it’s used for energy. Insulin resistance may lead to diabetes.
  • Obesity or being overweight. Excess weight typically worsens other heart disease risk factors.
  • Metabolic syndrome. Metabolic syndrome occurs when you have obesity, high blood pressure and high blood sugar. Having metabolic syndrome makes you twice as likely to develop heart disease than if you don’t have it.
  • Smoking. Nicotine tightens your blood vessels, and carbon monoxide can damage their inner lining, making them more susceptible to atherosclerosis. Heart attacks are more common in smokers than in nonsmokers.
  • Poor diet. A diet that’s high in fat, salt, sugar and cholesterol can contribute to the development of heart disease. A healthy diet can help reduce your risk of developing coronary heart disease and stop you gaining weight, reducing your risk of diabetes and high blood pressure.
  • Physical inactivity. Lack of exercise also is associated with many forms of heart disease and some of its other risk factors as well.
  • Ethnicity. African Americans, Mexican Americans, Native Americans, and native Hawaiians are at greater risk.
  • Family history. Arrhythmias can run in families. You may have an increased risk of some types of arrhythmias if a parent or other close relative has an arrhythmia.
  • Air pollution. Air pollution is harmful to your heart and circulation. Research shows that air pollution can affect your heart and circulation by:
    • damaging the inside walls of your blood vessels, causing them to become narrower and harder
    • restricting the movement of your blood vessels, which can increase your blood pressure and add to the strain on your heart
    • making your blood more likely to clot
    • affecting the normal electrical functioning of your heart which could cause abnormal heart rhythms
    • causing small changes to the structure of your heart like those that are seen in the early stages of heart failure.
    • This damage can contribute to the development of new health problems, or put people with existing heart and circulatory conditions at increased risk of events like a heart attack or stroke.
  • Stress. Unrelieved stress may damage your arteries and worsen other risk factors for heart disease. Research suggests that an emotionally upsetting event, particularly one involving anger, can serve as a trigger for a heart attack or angina in some people. Stress can contribute to high blood pressure and other heart disease risk factors. Some of the ways people cope with stress—drinking alcohol, using other substances, smoking, or overeating—are not healthy ways to manage stress.
  • Excessive use of alcohol. Drinking too much alcohol can affect the electrical impulses in your heart and can increase the chance of developing atrial fibrillation. Heavy drinking can also damage the heart muscle and worsen other coronary heart disease risk factors. Men should have no more than two drinks containing alcohol a day. Women should have no more than one drink containing alcohol a day. If you do not drink, you should not start. You should not drink if you are pregnant, are under the age of 21, taking certain medicines, or if you have certain medical conditions, including heart failure.
    • Alcohol can:
      • Add calories to your daily diet and possibly cause you to gain weight.
      • Raise your blood pressure and levels of triglyceride fats in your blood.
      • Contribute to or worsen heart failure in some people, such as some people who have cardiomyopathy.
      • Raise your risk of other diseases such as cancer.
  • Caffeine, nicotine or illegal drug use. Caffeine, nicotine and other stimulants can cause your heart to beat faster and may lead to the development of more-serious arrhythmias. Illegal drugs, such as amphetamines and cocaine, may greatly affect the heart and cause many types of arrhythmias or sudden death due to ventricular fibrillation.
  • Sex. Men are generally at greater risk of heart disease. The risk for women increases after menopause.
  • Electrolyte imbalance. Substances in the blood called electrolytes — such as potassium, sodium, calcium and magnesium — help trigger and send electrical impulses in the heart. An imbalance in electrolytes — for example, if they are too low or too high — can interfere with heart signaling and lead to irregular heartbeats.
  • Obstructive sleep apnea. Obstructive sleep apnea is a common disorder in which you have one or more pauses in breathing or shallow breaths while you sleep. Obstructive sleep apnea can lead to a slow heartbeat (bradycardia) and irregular heartbeats, including atrial fibrillation. Untreated sleep apnea can increase your risk for high blood pressure, diabetes, and even a heart attack or stroke.
  • Preeclampsia. Preeclampsia (high blood pressure during pregnancy) can occur during pregnancy. The two main signs of preeclampsia are a rise in blood pressure and excess protein in the urine. Preeclampsia is linked to an increased lifetime risk of heart disease, including coronary heart disease, heart attack, heart failure, and high blood pressure. Preeclampsia (high blood pressure during pregnancy) is a risk factor that you can’t control. However, if you’ve had the condition, you should take extra care to monitor your blood pressure and try to lower other heart disease risk factors.
  • An autoimmune condition. Having a condition such as rheumatoid arthritis or lupus can increase your risk of a heart attack.
  • Surgery. You may be at a higher risk of developing arrhythmias in the early days and weeks after surgery involving your heart, lungs, or throat.
  • Mental health problems. Some common mental health conditions include:

The good news is many heart and cardiovascular diseases are caused by risk factors that can be controlled, treated or modified.

Arrhythmia triggers

If you have any risk factors, certain situations may trigger an arrhythmia. These include any situations that make your heart work harder, raise your blood pressure, or cause your body to release stress hormones.

Triggers of heart arrhythmia may include:

  • Blood sugar levels that are too low or too high
  • Caffeine, illegal drugs, and medicines that make you more alert or increase your energy
  • Dehydration
  • Low levels of electrolytes, such as potassium, magnesium, or calcium
  • Physical activity
  • Strong emotional stress, anxiety, anger, pain, or a sudden surprise
  • Vomiting or coughing

Talk to your doctor about your triggers and what you can do to avoid them.

Arrhythmia prevention

You can help reduce your risk of heart disease which may help prevent heart arrhythmias by taking steps to control factors that put you at greater risk.

Your doctor may ask you to take some steps to help prevent them.

  • Control your blood pressure. Ask your doctor for a blood pressure measurement at least every two years. He or she may recommend more frequent measurements if your blood pressure is higher than normal or you have a history of heart disease. Optimal blood pressure is less than 120 systolic and 80 diastolic, as measured in millimeters of mercury (mm Hg).
  • Lower your cholesterol. Ask your doctor for a baseline cholesterol test when you’re in your 20s and then at least every five years. You may need to start testing earlier if high cholesterol is in your family. If your test results aren’t within desirable ranges, your doctor may recommend more-frequent measurements. Most people should aim for a low-density lipoprotein (LDL or “bad” cholesterol) level below 130 milligrams per deciliter (mg/dL), or 3.4 millimoles per liter (mmol/L). If you have other risk factors for heart disease, you should aim for an LDL level below 100 mg/dL (2.6 mmol/L). If you’re at very high risk of heart disease — if you’ve already had a heart attack or have diabetes, for example — aim for an LDL level below 70 mg/dL (1.8 mmol/L).
  • Keep diabetes under control. If you have diabetes, tight blood sugar control can help reduce the risk of heart disease.
  • Don’t smoke. Smoking is a major risk factor for heart disease, especially atherosclerosis. One of the best things you can do for your heart is to stop smoking or using smokeless tobacco. Quitting is the best way to reduce your risk of heart disease and its complications. Even if you’re not a smoker, be sure to avoid secondhand smoke. Chemicals in tobacco can damage your heart and blood vessels. Cigarette smoke reduces the oxygen in your blood, which increases your blood pressure and heart rate because your heart has to work harder to supply enough oxygen to your body and brain. There’s good news though. Your risk of heart disease starts to drop in as little as a day after quitting. After a year without cigarettes, your risk of heart disease drops to about half that of a smoker. No matter how long or how much you smoked, you’ll start reaping rewards as soon as you quit.
  • Don’t drink or limit your alcohol intake. Alcohol can cause abnormal heart rhythms, high blood pressure, damage to your heart muscle and other diseases such as stroke, liver problems and some cancers. Alcohol is also high in calories so it can lead to weight gain. It also lowers your inhibitions which might mean you find it harder to stick to your healthy eating plans when you have been drinking. If you are trying to lose weight, cut down on alcohol. Drinking more than the recommended amount of alcohol can have a harmful effect on your heart and general health.
  • Limiting or avoiding caffeine.
  • Get enough exercise. Regular, daily physical activity can lower your risk of heart disease. Physical activity helps you achieve and maintain a healthy weight and control diabetes, high cholesterol and high blood pressure — all risk factors for heart disease. If you have a heart arrhythmia or heart defect, there may be some restrictions on the activities you can do, so talk to your doctor. Exercise at least 30 to 60 minutes most days of the week. If you haven’t been active for a while, you may need to slowly work your way up to these goals, but in general, you should aim for at least:
    • 150 minutes a week of moderate aerobic exercise, such as walking at a brisk pace
    • 75 minutes a week of vigorous aerobic activity, such as running
    • Two or more strength training sessions a week
    • Even shorter bouts of activity offer heart benefits, so if you can’t meet those guidelines, don’t give up. Just five minutes of moving can help, and activities such as gardening, housekeeping, taking the stairs and walking the dog all count toward your total. You don’t have to exercise strenuously to achieve benefits, but you can see bigger benefits by increasing the intensity, duration and frequency of your workouts.
  • Get enough good-quality sleep. Quality sleep is good for your heart. It can be a challenge to make time for good sleep, but it’s important. For two weeks try to get 8 hours of good, quality sleep each night. Yes, each person’s sleep needs vary slightly, but eight is a good number to shoot for.
  • Eat healthy foods. A heart-healthy diet based on fruits, vegetables and whole grains — and low in saturated fat, salt (sodium), cholesterol and added sugar — can help you control your weight, blood pressure and cholesterol.
  • Maintain a healthy weight. Being overweight increases your risk of heart disease. A body mass index (BMI) of less than 25 and a waist circumference of 35 inches (88.9 centimeters) or less is the goal for preventing and treating heart disease.
  • Reduce and manage stress. Reduce stress as much as possible, as intense stress and anger can cause heart rhythm problems. Practice techniques for managing stress, such as muscle relaxation and deep breathing.
  • Get treatment for depression. Being depressed can increase your risk of heart disease significantly. Talk to your doctor if you feel hopeless or uninterested in your life.
  • Practice good hygiene. Regularly wash your hands and brush and floss your teeth to keep yourself well.
  • Get regular medical checkups. Early detection and treatment can set the stage for a lifetime of better heart health.
  • Using medications as directed and telling your doctor about all the medicines you take, including those bought without a prescription

Best diet for heart health

A heart-healthy eating plan includes:

  • Vegetables and fruits
  • Beans or other legumes
  • Lean meats and fish
  • Low-fat or fat-free dairy foods
  • Whole grains
  • Healthy fats, such as olive oil

The following foods are the foundation of a heart-healthy eating plan:

  • Vegetables such as leafy greens (spinach, collard greens, kale, cabbage), broccoli, and carrots
  • Fruits such as apples, bananas, oranges, pears, grapes, and prunes
  • Whole grains such as plain oatmeal, brown rice, and whole-grain bread or tortillas
  • Fat-free or low-fat dairy foods such as milk, cheese, or yogurt
  • Protein-rich foods:
  • Fish high in omega-3 fatty acids (salmon, tuna, and trout)
  • Lean meats such as 95% lean ground beef or pork tenderloin or skinless chicken or turkey
  • Eggs
  • Nuts, seeds, and soy products (tofu)
  • Legumes such as kidney beans, lentils, chickpeas, black-eyed peas, and lima beans
  • Oils and foods high in monounsaturated and polyunsaturated fats:
  • Canola, corn, olive, safflower, sesame, sunflower, and soybean oils (not coconut or palm oil)
  • Nuts such as walnuts, almonds, and pine nuts
  • Nut and seed butters
  • Salmon and trout
  • Seeds (sesame, sunflower, pumpkin, or flax)
  • Avocados
  • Tofu

Research shows that the best foods that protect your heart and blood vessels, include the following:

  • Fruits and Vegetables. Current World Health Organization (WHO) recommendations for fruit intake combined with vegetable intake are a minimum 400 g/day 24. A recent meta-analysis indicated that the intake of 800 g/day of fruit was associated with a 27% reductions in relative risk of cardiovascular disease 25.
  • Fatty fish (Omega-3 fatty acids). Omega-3 fatty acid is a polyunsaturated fatty acid that must be obtained through dietary intake from fish as well as other types of seafood as it is not produced naturally in the human body 26. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential fatty acids present in omega-3 27. Fatty fish such as salmon, sardines and mackerel are abundant sources of omega-3 fatty acids, healthy unsaturated fats that have been linked to lower blood levels of beta-amyloid—the protein that forms damaging clumps in the brains of people with Alzheimer’s disease. Omega-3 fatty acids are thought to help keep your blood vessels healthy and to help to reduce blood pressure. Research into this style of eating has shown a reduced risk of developing problems such as type 2 diabetes, high blood pressure and raised cholesterol, which are all risk factors for heart disease 28. The American Heart Association recommends eating 2 servings of fish (particularly fatty fish) per week. A serving is 3.5 ounce cooked, or about ¾ cup of flaked fish. Fatty fish like salmon, mackerel, herring, lake trout, sardines and albacore tuna are high in omega-3 fatty acids 29. Eating oily fish is a nutritious choice which can form part of the Mediterranean diet (more bread, fruit, vegetables, fish and less meat, and replacing butter with unsaturated fat spreads). Researchers have also found that people who closely follow a traditional Mediterranean style diet are more likely to live a longer life and also are less likely to become obese. Try to eat fish at least twice a week, but choose varieties that are low in mercury, such as salmon, cod, canned light tuna, and pollack. If you’re not a fan of fish, ask your doctor about taking an omega-3 supplement, or choose terrestrial omega-3 sources such as flaxseeds, avocados, and walnuts. Plant sources of omega-3 fatty acids include flaxseed, oils (olive, canola, flaxseed, soybean), nuts and other seeds (walnuts, butternut squash and sunflower). Replacements for vegans/vegetarians exist that are not supplements, but the evidence is not as robust for plant sources of omega-3 fatty acids.
  • Berries. Researchers credit the high levels of flavonoids in berries with the benefit 30. Flavonoids, the natural plant pigments that give berries their brilliant hues, also help improve memory, research shows. Berries contain a particularly high amount of flavonoids called anthocyanidins that are capable of crossing the blood brain barrier and localizing themselves in the hippocampus, an area of the brain known for memory and learning. Epidemiological evidence has established strong inverse associations between flavonoid-rich fruit (e.g. strawberries, grapefruit) and coronary heart disease mortality in cardiovascular disease-free postmenopausal women after multivariate adjustment 31. In a 20-year study of over 16,000 older adult women (aged ≥70 years), those who ate the most blueberries and strawberries had the slowest rates of cognitive decline by up to two-and-a-half years 30.
  • Walnuts. Nuts are excellent sources of protein, fat-soluble vitamin E and healthy fats, and one type of nut in particular might also improve memory. A 2015 study from UCLA linked higher walnut consumption to improved cognitive test scores. Walnuts are high in a type of omega-3 fatty acid called alpha-linolenic acid (ALA). Diets rich in alpha-linolenic acid and other omega-3 fatty acids have been linked to lower blood pressure and cleaner arteries. That’s good for both the heart and brain.
  • Meat-free meals. Heart-healthy eating encourages consuming meat sparingly. Beans, lentils and soybeans, which pack protein and fiber, make a worthy substitute. They’ll keep you full and are rich in B vitamins, which are important for brain health. In one study analyzing the diets of older adults, those who had the lowest intakes of legumes had greater cognitive decline than those who ate more.

The American Heart Association suggests these daily amounts:

  • Vegetables – canned, dried, fresh and frozen vegetables; 5 servings
  • Fruits – canned, dried, fresh and frozen fruits; 4 servings
  • Whole grains – barley, brown rice, millet, oatmeal, popcorn and whole wheat bread, crackers and pasta; 3-6 servings
  • Dairy – low fat (1%) and fat-free dairy products; 3 servings
  • Proteins – eggs, fish, lean meat, legumes, nuts, poultry and seeds; 1-2 servings. Eat a variety of fish at least twice a week, especially fish containing omega-3 fatty acids (for example, salmon, trout and herring).
  • Oils – polyunsaturated and monounsaturated canola, olive, peanut, safflower and sesame oil; 3 tablespoons
  • Limit – sugary drinks, sweets, fatty meats, and salty or highly processed foods
  • Choose foods with less salt (sodium) and prepare foods with little or no salt. To lower blood pressure, aim to eat no more than 2,300 milligrams of sodium per day. Reducing daily intake to 1,500 mg is desirable because it can lower blood pressure even further.
  • Limit saturated fat and trans fat and replace them with the better fats, monounsaturated and polyunsaturated. If you need to lower your blood cholesterol, reduce saturated fat to no more than 5 to 6 percent of total calories. For someone eating 2,000 calories a day, that’s about 13 grams of saturated fat.
  • Avoid – partially hydrogenated oils, tropical oils, and excessive calories
  • Replace – highly processed foods with homemade or less-processed options
  • If you drink alcohol, drink in moderation. That means no more than one drink per day if you’re a woman and no more than two drinks per day if you’re a man.

Arrhythmia signs and symptoms

Arrhythmias can produce a broad range of symptoms and results. The symptoms you have depend on what type of arrhythmia you have. For instance, a single premature beat may be felt as a “palpitation” or a “skipped beat.” Premature beats that occur often or in rapid succession may increase awareness of heart palpitations or a “fluttering” sensation in the chest or neck.

The most common symptoms of arrhythmia include:

  • rapid heartbeat or palpitations (a thumping or fluttering sensation in your chest)
  • alternating fast and slow heart rate
  • dizziness or lightheadedness
  • feeling as if you may ‘black out’ (near-fainting spells)
  • fainting
  • breathlessness
  • shortness of breath and anxiety
  • sweating
  • chest pain or pressure
  • feeling tired, fatigue or weak

In extreme cases, collapse and sudden cardiac arrest.

Important note: If you have chest pain or pressure, you may be having a heart attack. Call your local emergency services number immediately for a medical assistance and an ambulance. A heart attack occurs when the blood flow to your heart is blocked. This denies oxygen to the heart muscle — possibly damaging or destroying other organ tissues. The symptoms for heart attack can vary widely, just like symptoms for arrhythmia. Some heart attacks are sudden and intense. But most heart attacks start slowly, with mild pain or discomfort. Other symptoms can include:

  • Chest discomfort or pressure that may come and go
  • Discomfort in the upper body, including both arms, the back, stomach, neck and jaw
  • Shortness of breath, with or without chest discomfort
  • Cold sweat, nausea or lightheadedness

Symptoms of heart attack in women can be even subtler. Often those affected by heart attack, men and women alike aren’t sure what’s wrong and wait too long before getting help. If you think you may be having a heart attack, don’t delay. Get emergency help by calling your local emergency services number immediately for a medical assistance and an ambulance.

Arrhythmia complications

Arrhythmia complications depend on the type of arrhythmia. Arrhythmias that are not diagnosed or are left untreated can cause complications affecting your heart and brain. They may include:

  • Cardiac arrest: Arrhythmias can cause your heart to stop beating suddenly and unexpectedly.
  • Heart failure: Repeat arrhythmias cause cardiomyopathy, which can lead to heart failure. This is a serious condition that happens when your heart can’t pump enough blood to meet your body’s needs.
  • Problems with thinking and memory: Alzheimer’s disease and vascular dementia are more common in people who have arrhythmias. This may be because arrhythmias may reduce blood flow to your brain over time.
  • Stroke: With arrhythmias, blood can pool in the upper chambers of the heart, causing blood clots to form. If a clot breaks off and travels to the brain, it can cause a stroke.
  • Sudden infant death syndrome (SIDS): If born with an Inherited type of arrhythmia, your baby may have a higher risk of SIDS.
  • Worsening arrhythmias: Some arrhythmias can get worse over time or can trigger another type of arrhythmia.

In general, complications of heart arrhythmias may include stroke, sudden death and heart failure. Heart arrhythmias are associated with an increased risk of blood clots. If a clot breaks loose, it can travel from the heart to the brain, causing a stroke. Blood thinners can lower the risk of stroke related to atrial fibrillation and other arrhythmias. Your doctor will determine if a blood-thinning medication is right for you.

If an arrhythmia is causing heart failure symptoms, methods to control the heart rate may improve heart function.

Arrhythmia diagnosis

To diagnose a heart arrhythmia, the doctor will usually do a physical exam and ask questions about your medical history, lifestyle habits, and other risk factors of arrhythmias and symptoms. Tests may be done to confirm an irregular heartbeat and look for conditions that can cause arrhythmias, such as heart disease or thyroid disease.

Your physical exam may include these steps:

  • Checking for swelling in your legs or feet, which could be a sign of an enlarged heart or heart failure
  • Checking your pulse to find out how fast your heart is beating
  • Listening to the rate and rhythm of your heartbeat
  • Listening to your heart for a heart murmur
  • Looking for signs of other diseases, such as thyroid disease, that could be causing arrhythmias

If you or your child has a high risk of arrhythmias, your doctor may screen you regularly with heart tests. These tests, described in the next section, can help your doctor check whether your heartbeat is too fast, too slow, or irregular, even if you do not have any symptoms. Some of these tests may look at the heart’s structure and function or may determine if you have risk factors for developing an arrhythmia.

Tests to diagnose heart arrhythmias may include:

  • Blood tests to check for thyroid disorders, heart disease or other conditions linked to atrial tachycardia
  • Electrocardiogram (ECG or EKG). During an ECG, sensors (electrodes) that can detect the electrical activity of the heart are attached to the chest and sometimes to the arms or legs. An ECG measures the timing and duration of each electrical phase in the heartbeat.
  • Holter monitor. This portable ECG device can be worn for a day or more to record your heart’s activity as you go about your routine.
  • Event recorder. This wearable ECG device is used to detect sporadic arrhythmias. You press a button when symptoms occur. An event recorder may be worn for a longer period of time (up to 30 days or until you have an arrhythmia or typical symptoms).
  • Echocardiogram. In this noninvasive test, a hand-held device (transducer) placed on the chest uses sound waves to produce images of the heart’s size, structure and motion.
  • Implantable loop recorder. If symptoms are very infrequent, an event recorder may be implanted under the skin in the chest area to continually record the heart’s electrical activity and detect irregular heart rhythms.
  • Genetic testing. Genetic testing can check whether you have a type of arrhythmia that is caused by specific genes. This test is important when one or more of your close relatives has an arrhythmia caused by the same gene or had cardiac arrest.

If your doctor doesn’t find an arrhythmia during those tests, he or she may try to trigger the arrhythmia with other tests, which may include:

  • Stress test or exercise stress test. Some arrhythmias are triggered or worsened by exercise. During a stress test, the heart’s activity is monitored while you ride on a stationary bicycle or walk on a treadmill. If you have difficulty exercising, a drug may be given to stimulate the heart in a way that’s similar to exercise.
  • Tilt table test. A doctor may recommend this test if you’ve had fainting spells. Your heart rate and blood pressure are monitored as you lie flat on a table. The table is then tilted as if you were standing up. The doctor observes how your heart and the nervous system that controls it respond to the change in angle.
  • Electrophysiological testing and mapping. In this test, also called an EP study, a doctor threads thin, flexible tubes (catheters) tipped with electrodes through the blood vessels to different areas within the heart. Once in place, the electrodes can map the spread of electrical impulses through the heart. Sometimes, a heart doctor (cardiologist) uses the electrodes to stimulate the heart to beat at rates that may trigger — or stop — an arrhythmia. Doing this helps the doctor determine the location of the arrhythmia, its possible causes and the best treatment options. This test may also be done to determine if a person with certain health conditions is at risk of developing heart arrhythmias.
  • Heart imaging tests, such as computed tomography (CT) scans or cardiac magnetic resonance imaging (MRI), may check the structure of your heart chambers, show how well your heart is working, look for evidence of scar tissue in your heart muscle, or sometimes may look at your heart arteries.

Holter monitor

You can think of a Holter monitor (or continuous ambulatory electrocardiographic monitor) as a small, portable electrocardiogram (EKG or ECG) recorder. Holter monitors can record 24 hours or more of continuous electrocardiographic signals. This gives doctors a “movie” of the heart’s electrical activity, as opposed to the much shorter glimpse provided by an EKG. Your doctor may ask you to keep a diary of your activities and symptoms. Later, the Holter monitor results can be compared to your daily log to see how your activities or symptoms correspond to your measured heart rhythm.

Cardiac event recorder

For suspected arrhythmias that occur infrequently or pass quickly, your health care professional might suggest that you wear a cardiac event recorder.

Various kinds of event monitors attach with bracelets, finger clips or patches worn under the arms for a month or two. The data about your heart’s electrical system are recorded and stored. You can then transmit the results to your doctor to be analyzed.

Echocardiogram

An echocardiogram is a painless procedure that uses ultrasound waves to reveal your heart’s size, structure and motion. This type of echocardiography uses sound waves in much the same way that an ultrasound test uses sound waves to monitor a baby’s growth in the womb.

An echocardiogram often provides valuable information about a heart with an arrhythmia. The most common type of echocardiogram is transthoracic echocardiography (TTE).

Stress test or an exercise stress test

A stress test or an exercise stress test can help diagnose people whose suspected arrhythmias are caused by exercise.

In an exercise stress test, you walk or run on a treadmill or ride a stationary bicycle while your heart rate and rhythm are monitored. This can cause an arrhythmia, allowing your health care professional to study the abnormal heartbeat.

Tilt-table test

A tilt-table test may be suggested if you’ve suffered fainting spells. It reveals how your heart rate and blood pressure respond when changing positions from lying down to standing up.

In this test, a catheter may be placed in an artery to monitor blood pressure from within the blood vessel. An intravenous line (a small plastic tube in a vein) may also be started before the test.

If the cause of the fainting spells is not initially discovered, medications can be supplied through the intravenous line or by mouth to help produce the episodes.

Electrophysiologic testing

Electrophysiologic testing also called an EP study, can reveal suspected arrhythmias.

The electrophysiologic testing procedure is performed under local anesthesia where temporary electrode catheters are threaded through peripheral veins (or arteries) into the heart using a fluoroscope. These electrode catheters are positioned in the atria, ventricles or both. They record the heart’s electrical signals and “map” the path of electrical impulses during each heartbeat.

This test can cause known but infrequent arrhythmias, allowing them to be diagnosed. It can help trigger hidden tachycardia (fast heart rate) or bradycardia (slow heart rate).

Esophageal electrophysiologic procedure

In this procedure, a thin, flexible catheter is inserted into your nostril and positioned in the esophagus (the tube that connects the mouth and stomach). The catheter’s lead performs an electrocardiogram (EKG). The catheter’s proximity to the heart allows for more accurate results than a conventional EKG.

This procedure can cause unpredictable arrhythmias for diagnosis. Medications can be administered as part of the test to determine the most effective approach.

Arrhythmia treatment

Depending on the underlying cause of your heart arrhythmia, treatments may include medications, therapies such as vagal maneuvers, cardioversion, catheter procedures, implanted devices or heart surgery to control or eliminate fast (tachycardia), slow (bradycardia) or irregular heartbeats (fibrillation). Heart arrhythmia treatment is usually only needed if the irregular heartbeat is causing significant symptoms, or if the condition is putting you at risk of more-serious heart problems. The good news is that some arrhythmias are considered harmless and are left untreated. Your doctor may recommend regular checkups to monitor your condition.

Your doctor may talk to you about steps to manage the cause of your arrhythmia, such as a problem with your electrolytes levels, high blood pressure, heart disease, sleep apnea, or thyroid disease. Your doctor may use supplements to treat low levels of magnesium or potassium.

A heart-healthy lifestyle can also help prevent heart damage that can trigger certain heart arrhythmias. If you have heart disease or a heart condition, your doctor will likely recommend making lifestyle changes to keep your heart as healthy as possible.

Examples of heart-healthy lifestyle changes are:

  • Eat heart-healthy foods. Eat a healthy diet that’s low in salt and solid fats and rich in fruits, vegetables and whole grains.
  • Do regular physical activity. Aim to exercise for at least 30 minutes on most days.
  • Quit smoking. If you smoke and can’t quit on your own, talk to your doctor about strategies or programs to help you break a smoking habit.
  • Maintain a healthy weight. Being overweight increases the risk of developing heart disease. Lose excess weight if you’re overweight or obese.
  • Keep blood pressure and cholesterol levels under control. Make lifestyle changes and take medications as prescribed to manage high blood pressure or high cholesterol.
  • Drink alcohol in moderation. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger.
  • Maintain follow-up care. Take your medications as prescribed and have regular follow-up appointments with a doctor. Tell your doctor if your symptoms worsen.

Heart arrhythmias medications

Medications used to treat heart arrhythmias depend on the type of arrhythmia and potential complications. For example, drugs to control the heart rate and restore a normal heart rhythm are often prescribed for most people with tachycardia.

Antiarrhythmic drugs are grouped into four main classes according to the Vaughan-Williams classification scheme:

  • Class 1, Sodium-channel blockers
  • Class 2, Beta-blockers
  • Class 3, Potassium-channel blockers
  • Class 4, Calcium-channel blockers
  • Miscellaneous antiarrhythmics or unclassified antiarrhythmics.

The use of antiarrhythmic drug therapy must be balanced against two disadvantages. One is that the drugs must be taken daily and indefinitely. The other is the risk of side effects. While side effects are a risk of all medication, those associated with antiarrhythmic drugs can be very hard to manage. One such side effect is proarrhythmia, the more-frequent occurrence of preexisting arrhythmias or the appearance of new arrhythmias.

If you have atrial fibrillation, blood thinner (anticoagulant or antiplatelet) may be prescribed to prevent blood clots. It’s very important to take the medications exactly as directed by your doctor in order to reduce the risk of complications.

Calcium channel blockers

Calcium channel blockers also known as “calcium antagonists,” work by interrupting the movement of calcium into heart and blood vessel tissue. Calcium channel blockers block L-type calcium-channels; most effective at SA and AV nodes; reduce sinus rate and electrical conduction. Besides being used to treat high blood pressure, they’re also used to treat angina (chest pain) and/or some abnormal heart rhythms.

Examples of calcium channel blockers include:

  • Amlodipine (Norvasc)
  • Diltiazem (Cardizem, Tiazac, others)
  • Felodipine
  • Isradipine
  • Nicardipine
  • Nifedipine (Procardia)
  • Nisoldipine (Sular)
  • Verapamil (Calan SR, Verelan)

Calcium channel blockers can cause digestive trouble, swollen feet, or low blood pressure.

Beta blockers

Beta-blockers are drugs that bind to beta-adrenoceptors and thereby block the binding of norepinephrine and epinephrine to these receptors. This inhibits normal sympathetic effects that act through these receptors. Beta blockers decrease the heart rate and cardiac output, which lowers blood pressure by blocking the effects of epinephrine.

Beta-blockers are also used with therapy for cardiac arrhythmias and in treating angina pectoris.

Beta blockers can cause fatigue, stomach or sleep problems, and sexual dysfunction, and can make some arrhythmias worse.

Anticoagulants

Anticoagulants (blood thinners) work by making it harder for the blood to clot or coagulate. They aren’t designed to dissolve existing blood clots. They prevent new clots from forming or existing clots from getting larger. Because a common type of stroke is caused by a blood clot obstructing blood flow to the brain, anticoagulants are often prescribed for people with certain conditions to prevent a first stroke or to prevent recurrence of a stroke. Anticoagulants are also given to people at risk for forming blood clots, such as those with artificial heart valves or who have atrial fibrillation.

Digoxin

Digoxin is used to treat atrial fibrillation and heart failure. Digoxin is also used to treat heart pain (angina) and may be used after a heart attack. Digoxin helps the heart work better and it helps control your heart rate.

The major side effect of digoxin is cardiac arrhythmia, especially atrial tachycardias and atrioventricular block. Digoxin is contraindicated in patients who are hypokalemic, or who have atrioventricular block or Wolff-Parkinson-White (WPW) syndrome. Impaired renal function leads to enhanced plasma levels of digoxin because digoxin is eliminated by the kidneys. Lean, elderly patients are more susceptible to digoxin toxicity because they often have reduced renal function, and their reduced muscle mass increases plasma digoxin levels at a given dose because muscle Na+/K+-ATPase acts as a large binding reservoir for digoxin. A 2018 analysis of the AFFIRM trial determined that digoxin significantly increased all-cause mortality in patients with atrial fibrillation 32. This calls into question the practice of using digoxin for lowering ventricular rate in patients with atrial fibrillation.

Adenosine

Adenosine is a naturally occurring substance that relaxes and dilates blood vessels. Adenosine also affects the electrical activity of the heart. The major therapeutic use of adenosine is as an antiarrhythmic drug for the rapid treatment of supraventricular tachycardias caused by AV nodal reentry by suppressing AV nodal conduction. For these indications, adenosine is administered either as bolus intravenous injection or as an intravenous infusion. Adenosine is not effective for atrial flutter or fibrillation. Adenosine is also used during a stress test of the heart.

Most of adenosine’s side effects are related to its vasodilatory properties. Patients can experience flushing and headaches, both of which are related to vasodilation. Adenosine can produce rapid arterial hypotension; however, this is reversed shortly after stopping the infusion of adenosine because of its very short half-life. Coronary vascular steal is of theoretical concern in some patients with coronary artery disease, although there is no clinical evidence supporting this adverse effect. Methylxanthines such as caffeine and theophylline competitively antagonize the binding of adenosine at its purinergic receptor. Finally, adenosine may produce undesirable AV block; however, this is usually rapidly corrected by stopping adenosine administration. Therefore, adenosine is contraindicated in patients with preexisting second or third degree AV block.

Potassium channel blockers

Potassium channel blockers are a class of drugs used for treating arrhythmias. Potassium channel blockers also improve movement in people with multiple sclerosis. Potassium channel blockers used to treat arrhythmia include:

  • amiodarone: ventricular tachycardia, including ventricular fibrillation; atrial fibrillation and flutter (off-label use)
  • dronedarone: atrial fibrillation (non-permanent) and atrial flutter
  • dofetilide: atrial flutter and fibrillation; paroxysmal supraventricular tachycardia (off-label)
  • bretylium: life-threatening ventricular tachycardia and ventricular fibrillation
  • ibutilide: atrial flutter and fibrillation (acute termination)

Potassium channel blockers can cause low blood pressure, problems with your thyroid levels, lung conditions, or another type of arrhythmia.

Potassium channel blockers, are proarrhythmic as well as being antiarrhythmic. For example, the increase in action potential duration can produce torsades de pointes (a type of ventricular tachycardia), especially in patients with long-QT syndrome. Amiodarone, because of its Class IV effects (calcium-channel blockade), can cause bradycardia and atrioventricular block, and therefore is contraindicated in patients with heart block, or sinoatrial node dysfunction.

Sodium channel blockers

Sodium channel blockers act by inhibition of sodium influx through cell membranes. Blockade of sodium channels slows the rate and amplitude of initial rapid depolarization, reduces cell excitability, and reduces conduction velocity.

  • Class 1A sodium channel blockers used to treat atrial fibrillation, atrial flutter; supraventricular tachyarrhythmias (SVT) and ventricular tachyarrhythmias (VT): quinidine, procainamide and disopryamide
  • Class 1B sodium channel blockers used to ventricular tachyarrhythmias (VT): lidocaine, tocainide and mexiletine
  • Class 1C sodium channel blockers used to treat life-threatening supraventricular tachyarrhythmias (SVT) and ventricular tachyarrhythmias (VT): flecainide, propafenone and moricizine
  • Class 1D sodium channel blockers used to treat ventricular arrhythmias (premature ventricular complexes, PVC): ranolazine

The anticholinergic effects of 1A drugs can produce tachycardia, dry mouth, urinary retention, blurred vision and constipation. Diarrhea, nausea, headache and dizziness are also common side effects of many sodium channel blockers. Quinidine enhances digitalis toxicity, especially if hypokalemia is present. Quinidine, by delaying repolarization, can precipitate torsades de pointes (especially in patients with long-QT syndrome), a ventricular tachyarrhythmia caused by afterdepolarizations. Disopyramide is contraindicated for patients with uncompensated heart failure because of its negative inotropic actions; propafenone can also depress inotropy. 1C Sodium channel blockers can cause increased risk of sudden death in patients with a prior history of myocardial infarction or sustained ventricular arrhythmias.

Heart arrhythmias therapies

Therapies to treat heart arrhythmias include vagal maneuvers and cardioversion to stop the irregular heartbeat.

  • Vagal maneuvers. Vagal maneuvers include carotid sinus massage and valsalva maneuver, are techniques used to increase vagal parasympathetic tone in an attempt to diagnose and treat various arrhythmias 33. Vagal maneuvers affect the nervous system that controls your heartbeat (vagus nerves), often causing your heart rate to slow. If you have a very fast heartbeat due to supraventricular tachycardia (SVT), your doctor may recommend this therapy.  For example, you may be able to stop an arrhythmia by holding your breath and straining as if having a bowel movement for 10 to 15 seconds (also known as valsalva maneuver), dunking your face in ice water (also known as a diving reflex) or coughing. Vagal maneuvers don’t work for all types of arrhythmias.
    • Carotid Sinus Massage. The location of the carotid sinus is at the bifurcation of the internal and external carotid artery from the common carotid artery. The carotid sinus contains baroceptors that sense changes in blood pressure. Afferent signals are then transmitted via the glossopharyngeal nerve (cranial nerve 9) to the nucleus tractus solitarius (NTS) within the medulla. Within the aortic arch, there are baroreceptors that sense changes in aortic arterial pressure. These receptors send afferent signals to the nucleus tractus solitarius (NTS) via the vagus nerve. Within the heart, the right vagus nerve serves to stimulate the sinoatrial (SA) node, the pacemaker of the healthy heart, in the right atrium; this causes slowed electrical activity within the SA node. The left vagus nerve mostly innervates atrioventricular (AV) node, which slows conduction between the atria and the ventricles. The end product of vagal stimulation is a decrease in the speed and frequency of electrical impulses in the heart, which could ultimately slow or terminate a heart arrhythmia 34. To perform the carotid sinus massage, first find the carotid sinus at the arterial impulse just inferior to the angle of the mandible, anterior to the sternocleidomastoid, and the upper level of the thyroid cartilage. Use the fingertips of your index and middle finger to apply pressure in the posteromedial direction for 5 to 10 seconds. If unsuccessful, the procedure is repeatable after 1 minute. If still unsuccessful, you may attempt the maneuver on the opposite side. Possible responses to the carotid sinus massage include slowing of the your heart rate, termination of arrhythmia, or no response 33.
      • Avoid carotid sinus massage in patients with carotid bruits and patients with a history of transient ischemic attack (TIA) or stroke. Also, avoid it in patients who have experienced ventricular tachycardia, ventricular fibrillation, or myocardial infarction in the past three months 35. Older age is a relative contraindication because this population has a higher risk for carotid artery disease. Rarely, performing carotid sinus massage in patients with carotid artery disease may induce transient or permanent neurological symptoms. Simultaneous bilateral carotid sinus massage is contraindicated, given the risk of compromising cerebral circulation. Carotid sinus massage has not been studied in pediatric patients and is not recommended in children less than ten years old.
      • Neurologic complications following carotid sinus massage are rare and usually transient. The overall risk of stroke or embolic event with persistent neurological deficits is approximately 1 in 1000, enough to warrant obtaining informed consent before performing the procedure 35.
  • Cardioversion also called defibrillation when it is done in an emergency to prevent death when irregular heartbeats in the lower chambers of your heart, the ventricles, threatens to, or actually causes, cardiac arrest. Your doctor may also schedule cardioversion as a way to treat arrhythmias in the upper chambers of your heart, called atrial fibrillation. To prepare, you will be given anesthesia through an intravenous (IV) line in your arm to make you fall asleep, and you will have electrodes placed on your chest and possibly your back. These electrodes will be attached to the cardioversion machine. The machine records your heart’s electrical activity and sends the needed electrical shocks to your heart through paddles or patches on your chest. When ready, the doctor will send one or more brief, low-energy shocks to your heart to restore a normal rhythm. You will not feel any pain from the shocks. The current affects the electrical impulses in your heart and can restore a normal rhythm. You will need to stay for a few hours after your procedure. During this time, your healthcare team will monitor your heart rhythm and blood pressure closely and watch for complications. You will need a ride home because of the medicines or anesthesia you received. You may have some redness or soreness where the electrodes were placed. You also may have slight bruising where the IV line was inserted in your arm. Although uncommon, cardioversion has some risks. It can cause or worsen life-threatening arrhythmias that will need to be treated. This procedure can cause blood clots to break away and travel from the heart to other tissues or organs and cause a stroke or other problems. Taking anticlotting medicines before and after cardioversion can reduce this risk.

Heart arrhythmia surgery or procedures

If medicines do not treat your arrhythmia adequately, you may need one of the following procedures or devices. Treatment for heart arrhythmias may also involve catheter procedures or surgery to implant a heart (cardiac) device. Certain arrhythmias may require open-heart surgery.

Types of procedures and surgeries used to treat heart arrhythmias include:

  • Catheter ablation. Doctors perform catheter ablation in a hospital. Ablation is done through a procedure called cardiac catheterization that passes flexible tubes, or catheters, through your blood vessels until they reach your heart. Some catheters have wire electrodes that record and locate the source of your abnormal heartbeats. Other catheters can deliver treatments. Your doctor will aim the tip of a special catheter at the small area of heart tissue. A machine will send either radiofrequency (RF) waves, extremely cold temperatures, or laser light through the catheter tip to create a scar on the heart. The scar in your heart to block abnormal electrical signals and restore a normal heartbeat.
    • Catheter ablation has some risks both during the procedure and during recovery, including:
      • Bleeding
      • Infection
      • Blood vessel damage
      • Heart damage
      • Arrhythmias
      • Blood clots
      • There also may be a very slight risk of cancer from radiation used during catheter ablation. Talk to your doctor and the technicians performing the ablation about whether you are or could be pregnant.
  • Pacemaker. If slow heartbeats (bradycardias) don’t have a cause that can be corrected, doctors often treat them with a pacemaker because there aren’t any medications that can reliably speed up the heart. A pacemaker is a small device that’s usually implanted near the collarbone. One or more electrode-tipped wires run from the pacemaker through the blood vessels to the inner heart. If the heart rate is too slow or if it stops, the pacemaker sends out electrical impulses that stimulate the heart to beat at a steady rate.
  • Implantable cardioverter-defibrillator (ICD). Your doctor may recommend implantable cardioverter defibrillator (ICD) if you’re at high risk of developing a dangerously fast or irregular heartbeat in the lower heart chambers (ventricular tachycardia or ventricular fibrillation). If you have had sudden cardiac arrest or have certain heart conditions that increase your risk of sudden cardiac arrest, your doctor may also recommend an ICD. An implantable cardioverter-defibrillator (ICD) is a battery-powered unit that’s implanted under your skin near the collarbone — similar to a pacemaker. One or more electrode-tipped wires from the implantable cardioverter-defibrillator (ICD) run through veins to your heart. The implantable cardioverter-defibrillator (ICD) continuously monitors your heart rhythm. If the implantable cardioverter-defibrillator (ICD) detects an abnormal heart rhythm, it sends out low- or high-energy shocks to reset the heart to a normal rhythm. An implantable cardioverter-defibrillator (ICD) doesn’t prevent an irregular heart rhythm from occurring, but it treats it if it occurs.
  • Maze procedure. In the maze procedure, a surgeon makes a series of incisions in the heart tissue in the upper half of your heart (atria) to create a pattern (or maze) of scar tissue. Because scar tissue doesn’t conduct electricity, it interferes with stray electrical impulses that cause some types of arrhythmia. The maze procedure is usually reserved for people who don’t get better with other treatments or who are having open-heart surgery for other reasons.
  • Coronary bypass surgery. If you have severe coronary artery disease in addition to a heart arrhythmia, your doctor may perform coronary bypass surgery. This procedure may improve the blood flow to your heart.

Managing arrhythmias at home

  • Lie down if you feel dizzy or faint or if you feel palpitations. Do not try to walk or drive. Tell your doctor about these symptoms.
  • Talk to your doctor about techniques that you can do at home if you notice your heart racing.
  • Ask your doctor what types and amounts of exercise are safe for you. You may want to exercise in public or with a friend who can get help if necessary.
  • Learn how to take your pulse. Ask your doctor what pulse rate is normal for you. Keep a record of changes in your pulse rate and share this information with your doctor.
  • Carry a medical device ID card or wear a medical ID necklace or bracelet. These should have information about your condition and contact information for your doctor. This will help alert medical personnel and others about your condition if you have an emergency.
  • Have a plan in place for how to handle problems with your heart rhythm. Let others know that you might faint or your heart might stop beating. Tell them to call your local emergency services number right away if you have symptoms of serious complications.
  • Consider asking a loved one to learn cardiopulmonary resuscitation (CPR) in case your heart stops beating. You also may want to keep an automated external defibrillator (AED) with you at home or at work. This device uses electric shocks to restore a normal heart rhythm. Someone at your home or workplace should be trained in how to use the automated external defibrillator (AED). If a trained person isn’t available, an untrained person can also use the automated external defibrillator (AED) to help save your life.

Alternative medicine

Managing stress is an important step in keeping the heart healthy. Stress-relief techniques might also help prevent or reduce heart arrhythmias. Some ways to reduce stress include:

  • Yoga
  • Meditation or mindfulness
  • Relaxation techniques

Some research suggests that acupuncture may help reduce irregular heartbeats in people with persistent arrhythmias, but further research is needed.

Living with arrhythmias

Make healthy lifestyle changes

Your doctor may ask you to adopt lifelong heart-healthy lifestyle changes to help lower your risk of complications.

  • Aim for a healthy weight.
  • Choose heart-healthy foods.
  • Get regular physical activity.
  • Manage stress.
  • Quit smoking.

Your doctor may also ask you to reduce or stop drinking alcohol.

Get routine medical care

How often you need to see your doctor for follow-up care will depend on your symptoms and treatment.

  • Get treatment right away for conditions that can trigger or worsen arrhythmias.
  • Keep all your doctor’s appointments. Bring a list of all the medicines you take to every doctor and emergency room visit. This will help your doctors know exactly what medicines you are taking, which can help prevent medicine errors. You may need routine heart and blood tests to check how well your treatment is working. You may also need regular checkups to monitor your pacemaker or ICD.
  • Take your medicines as prescribed. Do not stop taking any medicines unless your doctor asks you to do so.
  • Tell your doctor if you have side effects from your medicines, such as depression, dizziness, or palpitations. Some medicines can cause low blood pressure or a slow heart rate or can make heart failure worse. Do not stop taking your medicines without talking to your doctor.
  • Tell your doctor if your symptoms are getting worse or if you have new symptoms. Over time, arrhythmias can become more common, last longer, or get worse. This can make your treatment not work as well as it used to work.

Take care of your mental health

Living with an arrhythmia may cause fear, anxiety, depression, and stress. Talk about how you feel with your healthcare team. Talking to a professional counselor can also help.

  • If you are depressed, you may need medicines or other treatments that can improve your quality of life.
  • Joining a patient support group may help you adjust to living with an arrhythmia. You can see how other people have coped with the condition. Talk to your doctor about local support groups or check with an area medical center.
  • Support from family and friends also can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.

Some people learn they have an arrhythmia because they get tested after a family member dies suddenly from this condition. Grief counseling may help you cope if this has happened to you. Talk with your doctor about finding a grief counselor.

Know your triggers

Your doctor may suggest taking these precautions, depending on what triggers your arrhythmia:

  • Avoid contact sports that might move your pacemaker or implantable defibrillator out of place.
  • Avoid high-intensity activities such as swimming or diving.
  • Avoid or limit caffeine, which is in coffee, tea, soda, and chocolate.
  • Change your alarm and phone ring tones to avoid sudden stress or loud noises.
  • Check with your doctor before taking over-the-counter medicines, nutritional supplements, or cold and allergy medicines.
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