Heart arrhythmia

Overview

A heart arrhythmia (uh-RITH-me-uh) is an irregular heartbeat. Heart rhythm problems (heart arrhythmias) occur when the electrical signals that coordinate the heart's beats don't work properly. The faulty signaling causes the heart to beat too fast (tachycardia), too slow (bradycardia) or irregularly.

Heart arrhythmias may feel like a fluttering or racing heart and may be harmless. However, some heart arrhythmias may cause bothersome — sometimes even life-threatening — signs and symptoms.

However, sometimes it's normal for a person to have a fast or slow heart rate. For example, the heart rate may increase with exercise or slow down during sleep.

Heart arrhythmia treatment may include medications, catheter procedures, implanted devices or surgery to control or eliminate fast, slow or irregular heartbeats. A heart-healthy lifestyle can help prevent heart damage that can trigger certain heart arrhythmias.

Types

In general, heart arrhythmias are grouped by the speed of the heart rate. For example:

  • Tachycardia (tak-ih-KAHR-dee-uh) is a fast heart. The resting heart rate is greater than 100 beats a minute.
  • Bradycardia (brad-e-KAHR-dee-uh) is a slow heartbeat. The resting heart rate is less than 60 beats a minute.

Fast heartbeat (tachycardia)

Types of tachycardias include:

  • Atrial fibrillation (A-fib). Chaotic heart signaling causes a rapid, uncoordinated heart rate. The condition may be temporary, but some A-fib episodes may not stop unless treated. A-fib is associated with serious complications such as stroke.
  • Atrial flutter. Atrial flutter is similar to A-fib, but heartbeats are more organized. Atrial flutter is also linked to stroke.
  • Supraventricular tachycardia. Supraventricular tachycardia is a broad term that includes arrhythmias that start above the lower heart chambers (ventricles). Supraventricular tachycardia causes episodes of a pounding heartbeat (palpitations) that begin and end abruptly.
  • Ventricular fibrillation. This type of arrhythmia occurs when rapid, chaotic electrical signals cause the lower heart chambers (ventricles) to quiver instead of contacting in a coordinated way that pumps blood to the rest of the body. This serious problem can lead to death if a normal heart rhythm isn't restored within minutes. Most people who have ventricular fibrillation have an underlying heart disease or have experienced serious trauma.
  • Ventricular tachycardia. This rapid, regular heart rate starts with faulty electrical signals in the lower heart chambers (ventricles). The rapid heart rate doesn't allow the ventricles to properly fill with blood. As a result, the heart can't pump enough blood to the body. Ventricular tachycardia may not cause serious problems in people with an otherwise healthy heart. In those with heart disease, ventricular tachycardia can be a medical emergency that requires immediate medical treatment.

Slow heartbeat (bradycardia)

Although a heart rate below 60 beats a minute while at rest is considered bradycardia, a low resting heart rate doesn't always signal a problem. If you're physically fit, your heart may still be able to pump enough blood to the body with fewer than 60 beats a minute at rest.

If you have a slow heart rate and your heart isn't pumping enough blood, you may have a type of bradycardia. Types of bradycardias include:

  • Sick sinus syndrome. The sinus node is responsible for setting the pace of the heart. If it doesn't work properly, the heart rate may alternate between too slow (bradycardia) and too fast (tachycardia). Sick sinus syndrome can be caused by scarring near the sinus node that's slowing, disrupting or blocking the travel of impulses. Sick sinus syndrome is most common among older adults.
  • Conduction block. A block of the heart's electrical pathways can cause the signals that trigger the heartbeats to slow down or stop. Some blocks may cause no signs or symptoms, and others may cause skipped beats or bradycardia.

Premature heartbeats

Premature heartbeats are extra beats that occur one at a time, sometimes in patterns that alternate with the normal heart beat. The extra beats may come from the top chamber of the heart (premature atrial contractions) or the bottom chamber (premature ventricular contractions).

A premature heartbeat may feel like your heart skipped a beat. These extra beats are generally not concerning, and they seldom mean you have a more serious condition. Still, a premature beat can trigger a longer-lasting arrhythmia, especially in people with heart disease. Occasionally, very frequent premature beats that last for several years may lead to a weak heart.

Premature heartbeats may occur when resting. Sometimes premature heartbeats are caused by stress, strenuous exercise or stimulants, such as caffeine or nicotine.

Typical heartbeat

In a typical heart rhythm, a tiny cluster of cells at the sinus node sends out an electrical signal. The signal then travels through the atria to the atrioventricular (AV) node and into the ventricles, causing them to contract and pump blood.

Symptoms

Heart arrhythmias may not cause any signs or symptoms. A doctor may notice the irregular heartbeat when examining you for another health reason.

In general, signs and symptoms of arrhythmias may include:

  • A fluttering in the chest
  • A racing heartbeat (tachycardia)
  • A slow heartbeat (bradycardia)
  • Chest pain
  • Shortness of breath

Other symptoms may include:

  • Anxiety
  • Fatigue
  • Lightheadedness or dizziness
  • Sweating
  • Fainting (syncope) or near fainting

When to see a 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.

A type of arrhythmia called ventricular fibrillation 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 911 or the emergency number in your area.
  • 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 AED. The AED will tell you what to do. It's programmed to allow a shock only when appropriate.

Causes

To understand the cause of heart arrhythmias, it may be helpful to know how the heart typically works.

How does the heart beat?

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

The heart's rhythm is normally controlled by a natural pacemaker (the sinus node) in the right upper chamber (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, 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.

Things that can cause an irregular heartbeat (arrhythmia) include:

  • 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
  • Diabetes
  • High blood pressure
  • Infection with COVID-19
  • Overactive thyroid gland (hyperthyroidism)
  • Sleep apnea
  • 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
  • Stress or anxiety

Risk factors

Things that may increase the risk of heart arrhythmias include:

  • Coronary artery disease, other heart problems and previous heart surgery. Narrowed heart arteries, a heart attack, abnormal heart valves, prior heart surgery, heart failure, cardiomyopathy and other heart damage are risk factors for almost any kind of arrhythmia.
  • High blood pressure. This condition increases the 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.
  • Congenital heart disease. Being born with a heart condition may affect the heart's rhythm.
  • Thyroid disease. Having an overactive or underactive thyroid gland can raise the risk of irregular heartbeats.
  • Obstructive sleep apnea. This condition causes pauses in breathing during sleep. It can lead to a slow heartbeat (bradycardia) and irregular heartbeats, including atrial fibrillation.
  • 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.
  • Certain drugs and supplements. Some prescription drugs and certain cough and cold medications bought without a prescription can cause arrhythmias.
  • Excessive alcohol. Drinking too much alcohol can affect the electrical impulses in your heart and can increase the chance of developing atrial fibrillation.
  • 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.

Complications

Complications depend on the 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.

Prevention

Lifestyle changes to reduce the risk of heart disease may help prevent heart arrhythmias. A heart-healthy lifestyle includes:

  • Eating a heart-healthy diet
  • Staying physically active
  • Maintaining a healthy weight
  • Not smoking
  • Limiting or avoiding caffeine and alcohol
  • Reducing stress, as intense stress and anger can cause heart rhythm problems
  • Using medications as directed and telling your doctor about all the medicines you take, including those bought without a prescription

Diagnosis

To diagnose a heart arrhythmia, the doctor will usually do a physical exam and ask questions about your medical history 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.

Tests to diagnose heart arrhythmias may include:

  • 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.

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. 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.

Treatment

Treatment for heart arrhythmias depends on whether you have a fast heartbeat (tachycardia) or slow heartbeat (bradycardia). Some heart arrhythmias do not need treatment. Your doctor may recommend regular checkups to monitor your condition.

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. Treatment for heart arrhythmias may include medications, therapies such as vagal maneuvers, cardioversion, catheter procedures or heart surgery.

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.

If you have atrial fibrillation, blood thinners 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.

Therapies

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

  • Vagal maneuvers. If you have a very fast heartbeat due to supraventricular tachycardia, your doctor may recommend this therapy. Vagal maneuvers affect the nervous system that controls your heartbeat (vagus nerves), often causing your heart rate to slow. For example, you may be able to stop an arrhythmia by holding your breath and straining, dunking your face in ice water, or coughing. Vagal maneuvers don't work for all types of arrhythmias.
  • Cardioversion. This method to reset the heart rhythm may be done with medications or as a procedure. Your doctor may recommend this treatment if you have a certain type of arrhythmia, such as atrial fibrillation.

    During the cardioversion procedure, a shock is delivered to your heart through paddles or patches on your chest. The current affects the electrical impulses in your heart and can restore a normal rhythm.

Surgery or other procedures

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. In this procedure, the doctor threads one or more catheters through the blood vessels to the heart. Electrodes at the catheter tips use heat or cold energy to create tiny scars in your heart to block abnormal electrical signals and restore a normal heartbeat.
  • 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 this device 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 ICD is a battery-powered unit that's implanted under the skin near the collarbone — similar to a pacemaker. One or more electrode-tipped wires from the ICD run through veins to the heart. The ICD continuously monitors your heart rhythm.

    If the ICD detects an abnormal heart rhythm, it sends out low- or high-energy shocks to reset the heart to a normal rhythm. An 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.
Cardiac catheter ablation

In catheter ablation, catheters are threaded through the blood vessels to the inner heart, and electrodes at the catheter tips map the spread of electrical impulses through the heart. Electrodes at the catheter tips transmit energy to destroy a small spot of heart tissue and create an electrical block along the pathway that's causing your arrhythmia.

Pacemakers, defibrillator

A dual chamber pacemaker paces the atrium and ventricle. A biventricular pacemaker paces both ventricles. An implantable cardioverter-defibrillator can work as a pacemaker would. In addition, if it detects ventricular tachycardia or ventricular fibrillation, it sends out a shock to reset the heart to a normal rhythm.

Lifestyle and home remedies

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.
  • Exercise regularly. 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.
  • 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.

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.

Preparing for an appointment

If you think you may have a heart arrhythmia, make an appointment with your doctor. If a heart arrhythmia is found early, treatment may be easier and more effective. You may be referred to a doctor trained in heart conditions (cardiologist).

If a heart arrhythmia persists for more than a few minutes or is accompanied by fainting, shortness of breath or chest pain, call 911 or your local emergency number or have someone drive you to the nearest emergency room.

Because appointments can be brief, and because there's often a lot to discuss, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.

What you can do

  • Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet. You may need to do this if your doctor orders any blood tests.
  • Write down any symptoms you're having, including any that may seem unrelated to heart arrhythmia.
  • Write down key personal information, including a family history of heart disease, stroke, high blood pressure or diabetes, and any major stresses or recent life changes.
  • Make a list of all medications, including vitamins or supplements that you're taking.
  • Take a family member or friend along, if possible. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For heart arrhythmias, some basic questions to ask your doctor include:

  • What's the most likely cause of my symptoms?
  • Are there other possible causes for my symptoms?
  • What kinds of tests will I need? Do I need to do anything to prepare for these tests?
  • What's the most appropriate treatment?
  • Are there any foods or drinks that you recommend I avoid? Is there anything you suggest that I add to my diet?
  • What's an appropriate level of physical activity?
  • How often should I be screened for heart disease or other complications of an arrhythmia?
  • I have other health conditions. How can I best manage these conditions together?
  • Is there a generic alternative to the medicine you're prescribing?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:

  • When did you first begin experiencing symptoms?
  • Have your symptoms been continuous, or do they come and go?
  • How severe are your symptoms?
  • Does anything seem to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
  • Is there a family history of arrhythmia?

Last Updated Oct 1, 2021


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