What is an arrhythmia?
An arrhythmia (also called dysrhythmia) is an irregular or abnormal heartbeat.
What are the types of arrhythmias?
- Supraventricular arrhythmias: Arrhythmias that begin in the atria (the heart’s upper chambers). "Supra” means above. “Ventricular” refers to the lower chambers of the heart or ventricles.
- Ventricular arrhythmias: Arrhythmias that begin in the ventricles (the heart’s lower chambers).
- Bradyarrhythmias: Slow heart rhythms that may be caused by disease in the heart’s conduction system, such as the sinoatrial (SA) node, atrioventricular (AV) node or HIS-Purkinje network.
What are the types of supraventricular arrhythmias?
Supraventricular arrhythmias begin in the atria or the upper chambers of your heart. Types of supraventricular arrhythmias include:
- Paroxysmal supraventricular tachycardia (PSVT): A rapid but regular heart rhythm that comes from the atria. This type of arrhythmia begins and ends suddenly.
- Accessory pathway tachycardias (bypass tract tachycardias): A fast heart rhythm caused by an extra, abnormal electrical pathway or connection between the atria and ventricles. The impulses travel through the extra pathways as well as the usual route. This allows the impulses to travel around your heart very quickly, causing it to beat unusually fast (example: Wolff- Parkinson-White syndrome).
- AV nodal re-entrant tachycardia (AVNRT): A fast heart rhythm caused by the presence of more than one pathway through the atrioventricular (AV) node.
- Atrial tachycardia: A rapid heart rhythm that starts in the atria.
- Atrial fibrillation: A very common irregular heart rhythm. This happens when many impulses begin and spread through the atria, competing for a chance to travel through the AV node. This results in a disorganized rapid and irregular rhythm. Because the impulses are traveling through the atria in a disorderly fashion, there’s a loss of coordinated atrial contraction.
- Atrial flutter: An atrial arrhythmia caused by one or more rapid circuits in the atrium. Atrial flutter is usually more organized and regular than atrial fibrillation.
What are the types of ventricular arrhythmias?
A ventricular arrhythmia begins in the heart’s ventricles. Types of ventricular arrhythmias include:
- Premature ventricular contractions (PVCs): Early, extra heartbeats that start out in the ventricles. Most of the time, PVCs don’t cause any symptoms or require treatment. This type of arrhythmia is common and can be related to stress, too much caffeine or nicotine, or exercise. They can be also be caused by heart disease or electrolyte imbalance. People who have several PVCs and/or symptoms associated with them should be evaluated by a cardiologist (heart doctor).
- Ventricular tachycardia (V-tach): A rapid heartbeat that begins in the ventricles. The rapid rhythm keeps the heart from adequately filling with blood, and less blood is able to pump through the body. V-tach can be serious, especially in people with heart disease, and may be associated with more symptoms than other types of arrhythmia. A cardiologist should evaluate this condition.
- Ventricular fibrillation (V-fib): An erratic, disorganized firing of impulses from the ventricles. The ventricles quiver and can’t generate an effective contraction, which results in a lack of blood being delivered to your body. This is a medical emergency that must be treated with cardiopulmonary resuscitation (CPR) and defibrillation (delivery of an energy shock to your heart muscle to restore a normal rhythm) as soon as possible.
- Long QT: While this is not an arrhythmia, it can predispose someone to have one. The QT interval is the area on the ECG that represents the time it takes for the heart muscle to contract and then recover, or for the electrical impulse to fire and then recharge. When the QT interval is longer than normal, it increases the risk for “torsade de pointes,” a life-threatening form of ventricular tachycardia.
What are the types of bradyarrhythmias?
A bradyarrhythmia is a slow heart rhythm that is usually caused by disease in the heart’s conduction system. Types of bradyarrhythmias include:
- Sinus node dysfunction: Slow heart rhythms due to an abnormal SA node.
- Heart block: A delay or complete block of the electrical impulse as it travels from the sinus node to the ventricles. The level of the block or delay may occur in the AV node or HIS-Purkinje system. The heartbeat may be irregular and slow.
Symptoms and Causes
What are the symptoms of an arrhythmia?
An arrhythmia may be “silent” and not cause any symptoms. A doctor can find an irregular heartbeat during an examination by taking your pulse, listening to your heart or performing diagnostic tests. If symptoms occur, they may include:
- ++Palpitations++: A feeling of skipped heartbeat or that your heart is “running away,” fluttering or doing "flip-flops.”
- Pounding in your chest.
- Dizziness or feeling lightheaded.
- Shortness of breath.
- Chest discomfort.
- Weakness or fatigue (feeling very tired).
- Weakening of the heart muscle or low ejection fraction.
What causes arrhythmias?
Arrhythmias can be caused by:
- Coronary artery disease.
- Irritable tissue in the heart (due to genetic or acquired causes).
- High blood pressure.
- Changes in the heart muscle (cardiomyopathy).
- Valve disorders.
- Electrolyte imbalances in your blood, such as sodium or potassium imbalances.
- Injury from a heart attack.
- The healing process after heart surgery.
- Other medical conditions.
Diagnosis and Tests
How is an arrhythmia diagnosed?
If you have symptoms of an arrhythmia, you should make an appointment with a cardiologist. You may want to see an electrophysiologist — a cardiologist who has additional specialized training in the diagnosis and treatment of heart rhythm disorders. After assessing your symptoms and performing a physical examination, the cardiologist may perform a variety of diagnostic tests to help confirm the presence of an arrhythmia and indicate its causes. Some tests that may be done to confirm the presence of an irregular heart rhythm include:
- Electrocardiogram (ECG or EKG): A picture of the electrical impulses traveling through the heart muscle. An ECG is recorded on graph paper, through the use of electrodes (small, sticky patches) that are attached to your skin on the chest, arms and legs.
- Ambulatory monitors, such as the Holter monitor.
- Stress test: A test used to record arrhythmias that start or are worsened with exercise. This test also may be helpful to determine if there is underlying heart disease or coronary artery disease associated with an arrhythmia.
- Echocardiogram: A type of ultrasound used to provide a view of the heart to determine if there is heart muscle or valve disease that may be causing an arrhythmia. This test may be performed at rest or with activity.
- Cardiac catheterization: Using a local anesthetic, a catheter (small, hollow, flexible tube) is inserted into a blood vessel and guided to the heart with the help of an X-ray machine. A contrast dye is injected through the catheter so X-ray movies of your coronary arteries, heart chambers and valves may be taken. This test helps your doctor determine if the cause of an arrhythmia is coronary artery disease. This test also provides information about how well your heart muscle and valves are working.
- Electrophysiology study (EPS): A special heart catheterization that evaluates your heart’s electrical system. Catheters are inserted into your heart to record the electrical activity. The EPS is used to find the cause of the abnormal rhythm and determine the best treatment for you. During the test, the arrhythmia can be safely reproduced and terminated.
- Tilt table test (also called a passive head-up tilt test or head upright tilt test): Records your blood pressure and heart rate on a minute-by-minute basis while the table is tilted in a head-up position at different levels. The test results may be used to evaluate heart rhythm, blood pressure and sometimes other measurements as you change position.
Management and Treatment
How is an arrhythmia treated?
Treatment depends on the type and severity of your arrhythmia. In some cases, no treatment is necessary. Treatment options include medications, lifestyle changes, invasive therapies, electrical devices or surgery.
What medications treat arrhythmias?
A variety of drugs are available to treat arrhythmias. Because everyone is different, it may take trials of several medications and doses to find the one that works best for you. Several types of drugs are used:
- Anti-arrhythmic drugs are drugs used to convert the arrhythmia to sinus rhythm (normal rhythm) or to prevent an arrhythmia.
- Heart-rate control drugs are drugs used to control the heart rate.
- Anticoagulant or antiplatelet therapy are drugs, such as warfarin (a blood thinner) or aspirin, that reduce the risk of clots forming or having strokes.
- Medications used to treat related conditions that may be causing an abnormal heart rhythm.
It’s important to know:
- The names of your medications.
- What they are for.
- How often and at what times to take them.
What invasive therapies are used to treat arrhythmias?
Electrical cardioversion and catheter ablation are invasive therapies used to treat or eliminate irregular heart rhythms. Your doctor will determine the best treatment for you and discuss the benefits and risks of these therapies with you.
In people with persistent past or irregular arrhythmias (such as atrial fibrillation), a normal rhythm may not be achieved with drug therapy alone. Cardioversion is performed by the doctor in a special procedure room. After administration of a short-acting anesthesia, an electrical impulse is delivered through your chest wall that synchronizes the heart and allows the normal rhythm to restart.
During a catheter ablation, high-frequency electrical energy is delivered through a catheter to a small area of tissue inside of the heart that causes the abnormal heart rhythm. This energy "disconnects" the pathway of the abnormal rhythm. Ablation can be used to treat most SVTs, atrial flutter, and some atrial and ventricular tachycardias. It can also be used to disconnect the electrical pathway between the atria and the ventricles, which may be useful in people with atrial fibrillation. Ablation may be combined with other procedures to achieve optimal treatment.
Pulmonary vein isolation
In people with frequent, paroxysmal or persistent atrial fibrillation, isolation of the pulmonary veins (pulmonary vein isolation) is a type of ablation that targets areas thought to cause atrial fibrillation. The goal is to create rings of scar that isolate the foci responsible for triggering atrial fibrillation.
What devices are used to treat arrhythmias?
A cardiologist may insert certain devices during a procedure in the electrophysiology lab.
A permanent pacemaker is a device that sends small electrical impulses to the heart muscle to maintain a normal heart rate. The pacemaker has a pulse generator (which houses a battery and a tiny computer) and leads (wires) that send impulses from the pulse generator to the heart muscle, as well as sense the heart's electrical activity. Pacemakers are mostly used to prevent your heart from beating too slowly.
An implantable cardioverter-defibrillator (ICD) is a sophisticated device used primarily to treat ventricular tachycardia and ventricular fibrillation, two life-threatening heart rhythms. The ICD constantly monitors the heart rhythm. When it detects a very fast, abnormal heart rhythm, it delivers energy to the heart muscle to cause the heart to beat in a normal rhythm again.
There are several ways the ICD can be used to restore normal heart rhythm. These include:
- Anti-tachycardia pacing (ATP): When the heart beats too fast, a series of small electrical impulses may be delivered to the heart muscle to restore a normal heart rate and rhythm.
- Cardioversion/defibrillation: When the heart is beating dangerously fast or irregularly, a shock may be delivered to the heart muscle to restore a normal rhythm.
- Anti-bradycardia pacing: Most ICDs provide backup pacing to prevent too slow of a heart rhythm.
Biventricular (B-V) pacemakers and defibrillators(also called cardiac resynchronization therapy or CRT) are used in people with heart failure who also have evidence of an uncoordinated or out-of-sync contraction of the left ventricle. These devices help to synchronize the contraction of the left ventricle. In addition to the one or two leads used by traditional pacemakers and defibrillators that are placed in the right ventricle and right atrium, bi-ventricular devices utilize an additional lead placed on the back or left side of the left ventricle. To reach this area, the additional lead is typically guided through the coronary sinus, a small vein on the back of the heart.
People with arrhythmias may require heart surgery for any of these reasons:
- An individual may need heart surgery to treat heart disease that may be causing the arrhythmia, including valve surgery or coronary artery bypass surgery.
- The Maze and modified Maze procedures are two surgeries used to correct atrial fibrillation not controlled with medications or nonsurgical treatment methods. It’s often used when other types of heart surgery such as valve surgery are planned. In some cases, these procedures can be performed on their own.
- In some cases, biventricular pacemaker leads may be placed on the heart using minimally invasive or endoscopic techniques.
What are some lifestyle-related risk factors for arrhythmias?
Here are some ways to change these arrhythmia risk factors that are related to arrhythmias.
- If you smoke or use tobacco products, quit.
- Limit your intake of alcohol.
- Limit or stop using caffeine. Some people are sensitive to caffeine and may notice more symptoms when using caffeinated products (such as tea, coffee, colas and some over-the-counter medications).
- Don’t take stimulants. Beware of stimulants used in cough and cold medications and herbal or nutritional supplements. Some of these medications contain ingredients that promote irregular heart rhythms. Read the label and ask your doctor or pharmacist what medication would be best for you.
- Control high blood pressure.
- If you have obesity, working toward a weight that's healthy for you can lower your risk for arrhythmia.
- Control blood sugar levels.
- Treat sleep apnea. Treatment may decrease your risk for arrhythmia.
- If you notice that your irregular heart rhythm occurs more often with certain activities, you should avoid them.
When should I contact my healthcare provider if I have an arrhythmia?
You’ll need to visit your doctor for regular follow-up visits to:
- Make sure your arrhythmia is controlled.
- Properly adjust your medications.
- Evaluate the function of any implanted devices.
- Make sure you’re staying healthy and not having other medical problems.
Your provider will tell you how often you should visit. Call your doctor in between visits if your symptoms become more frequent or severe.
You should also make sure that your family and friends know how to recognize your symptoms. They should also learn how to start CPR if that ever becomes necessary.
What should I know about self-care with an arrhythmia?
If you have an arrhythmia, or even if you don’t, you might find it useful to know how to take your pulse. Your pulse indicates your heart rate or the number of times your heart beats in one minute. Pulse rates vary from person to person. Your pulse is slower when you are at rest and increases when you exercise since more oxygen-rich blood is needed by the body during exercise.
How do I take my pulse?
You can tell how fast your heart is beating by feeling your pulse. You can feel your pulse on your wrist or neck. Place the tips of your index and middle fingers on the inner wrist of your other arm, just below the base of your thumb. Or, place the tips of your index and middle fingers on your lower neck, on either side of your windpipe. Press lightly with your fingers until you feel the blood pulsing beneath your fingers. You may need to move your fingers around slightly up or down until you feel the pulsing.
You can count the number of beats in 10 seconds and multiply by six to determine your heart rate in beats per minute. A normal heart rate, at rest, is 50 to 100 beats per minute.
A note from Cleveland Clinic
There are many ways for your heartbeat to be irregular. Some of these irregular heartbeats, called arrhythmias, don’t cause symptoms. It’s important that you see your healthcare provider if you do notice symptoms like extreme fatigue or heart palpitations. Your provider will help you decide on the best treatment option for you, but you can help yourself by making appropriate lifestyle changes.
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