Medically Reviewed By William C. Lloyd III, MD, FACS

What are arrhythmias?

If fluttering or pounding in your chest makes you feel dizzy or short of breath, you might have a cardiac arrhythmia. There are many different types of abnormal heartbeat rhythms, some of which are more dangerous than others. Arrhythmias are caused by a multitude of underlying conditions and poor lifestyle choices, but treatment is often successful.

Arrhythmia is the medical name for a disorder of your heart rate (pulse) or heart rhythm, such as beating too fast (tachycardia) or too slow (bradycardia). An irregular heartbeat is another sign of an arrhythmia.

Arrhythmias are caused by an abnormality in the conduction of nerve signals (impulses) within the heart muscle that affects the way the heart beats. Most arrhythmias are harmless, but others can be serious or even life-threatening. If the heart rate is too fast, too slow, or irregular, the heart may not be able to effectively pump enough freshly-oxygenated blood to the body. Lack of blood flow can damage the brain, heart, and other organs due to a lack of oxygen.

The signs and symptoms of arrhythmias can be brief or last indefinitely. Some people have no symptoms at all, while others may have severe arrhythmia symptoms that compromise the cardiopulmonary system.

Left untreated, heart arrhythmias may lead to chest pain, heart attack, heart failure, and stroke. Seek immediate medical care (call 911) for serious symptoms, such as severe chest pain or pressure, sweating, and severe difficulty breathing, which may be combined with pale or bluish lips, fast heart rate, and anxiety. Seek prompt medical care if you are being treated for an arrhythmia but mild symptoms, such as fatigue, palpitations, or an irregular heartbeat, recur or are persistent.

What are the different types of arrhythmia?

Normally, your heart beats in a regular rhythm at a rate between 60 to 100 beats per minute. Your heart rate naturally increases when you exercise or have stress and slows down when you are relaxed or are at rest. An arrhythmia is an abnormal heart rhythm that is either too fast, too slow, or irregular. Arrhythmias can be mild to severe to life-threatening.

Types of arrhythmias include:

  • Atrial fibrillation is an irregular, unusually rapid beating of the upper chambers of the heart, or atria; it is the most common type of arrhythmia.
  • Bradycardia is an abnormally slow heartbeat, generally slower than 60 beats per minute. This can be normal in some cases, such as in trained athletes or when you are deeply relaxed.
  • Heart block, or atrioventricular block, refers to a variety of arrhythmias caused by a “blockage” in your heart’s electrical system transmitting signals from the upper to the lower chambers.
  • Multifocal atrial tachycardia is an arrhythmia in which different areas of the upper chambers of the heart attempt to signal at once.
  • Paroxysmal supraventricular tachycardia is a very rapid heart rhythm that occurs suddenly and comes and goes.
  • Sick sinus syndrome is a group of different heart rhythm problems that is most common in older people.
  • Tachycardia is an abnormally fast heartbeat, generally faster than 100 beats per minute. This can be normal if it occurs when you exercise or are under stress, and if it returns to normal at rest or when the stress has passed.
  • Ventricular fibrillation is a life-threatening condition in which the lower chambers of the heart beat rapidly and uncontrollably.
  • Ventricular tachycardia is a very rapid heart rhythm, originating in the lower chambers of the heart, that can lead to ventricular fibrillation, an ineffective quivering of your heart. This can cause cardiac arrest, in which your heart stops beating or is beating too inefficiently to maintain an adequate circulation.

What are the symptoms of arrhythmias?

An arrhythmia can cause your heart to be ineffective or weak, resulting in not enough blood getting to your body. Arrhythmias may produce a broad range of symptoms, from barely noticeable to life-threatening. Arrhythmia symptoms can vary in intensity among individuals. Sometimes, people with arrhythmias don’t feel any symptoms.

Common symptoms of arrhythmias

A single premature beat may be felt as a palpitation or skipped beat. Common symptoms include:

  • Awareness of the heart beating
  • Heart palpitations or a fluttering sensation in the chest or neck
  • Premature beats that occur often or in rapid succession

Other symptoms of arrhythmias

When arrhythmias last long enough to affect how well the heart works, more serious symptoms may develop:

  • Chest pain
  • Dizziness
  • Fainting or change in level of consciousness or lethargy
  • Lightheadedness
  • Pale skin or pallor
  • Rapid breathing (tachypnea) or shortness of breath
  • Rapid heart rate (tachycardia)
  • Skipping beats (changes in the pattern of the pulse)
  • Sweating

Serious symptoms that might indicate a life-threatening condition

In some cases, arrhythmias can be life-threatening. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

  • Chest pain and pressure that may radiate from the chest down the arm
  • Confusion or loss of consciousness for even a moment
  • Dizziness
  • Irregular heartbeat
  • Rapid heart rate (tachycardia)
  • Slow heart rate (bradycardia)

What causes arrhythmias?

Arrhythmias are caused by problems with the heart’s electrical conduction system. The heart has its own pacemaker that normally sends out the signals to control the heartbeat, but other areas of the heart’s electrical system also may send out signals. When other areas of the heart start to send signals to beat, the heart rhythm is altered.

At other times, electrical signals cannot be transmitted throughout the heart muscles as easily or at all. Different nerve messages may cause your heart to beat too slowly (bradycardia), too quickly (tachycardia), or irregularly. Problems can occur anywhere along the nerve conduction system within the heart, causing various arrhythmias.

Arrhythmia causes include:

  • Genetic conditions, such as Wolff-Parkinson-White syndrome. WPW causes an abnormal nerve conduction pathway from the upper to lower chambers of the heart, triggering a rapid heartbeat. WPW is a rare condition present at birth. Other types of genetic defects can cause or increase the risk of developing arrhythmias.
  • Lifestyle habits. Smoking, excessive exercise, and drinking too much caffeine can contribute to or trigger an arrhythmia.
  • Medications and drugs, including stimulants, certain prescribed drugs, herbal drugs, diet drugs, and cocaine can cause an arrhythmia.
  • Older age. Increasing age correlates with decreasing heart function, even in otherwise healthy individuals.

What are the risk factors for arrhythmias?

Anyone can get an arrhythmia, but several factors increase the risk of developing arrhythmias. Not all people with risk factors will develop an arrhythmia.

People with the highest risk of developing an arrhythmia include those with the following conditions:

  • High blood pressure

Other things that can trigger arrhythmias include:

  • Blood chemistry imbalances, such as hyperkalemia (abnormal potassium levels)
  • Certain substances or drugs, including amphetamines, caffeine, cocaine, and some prescription medications
  • Electrolyte imbalances

How do you prevent or reduce your risk of an arrhythmia?

Keep in mind that not all people with risk factors will develop an arrhythmia. If you are at risk for an arrhythmia, talk with your doctor about ways to reduce your risk. If you have a history of arrhythmia, here are things you can do yourself to help manage or prevent arrhythmia:

  • Stop smoking. Talk with your doctor about smoking cessation programs and medications, such as nicotine patches.
  • Take your daily heart medication exactly as prescribed.
  • Don’t misuse stimulant medications or use street drugs.
  • Control your stress level. Take time for yourself and do something to relax. Choose a calming activity that you can enjoy, such as yoga, shopping, or getting a massage.
  • Go easy on alcohol and caffeine. Follow your doctor’s instructions for how much, if any, is okay for you.
  • Call 911 immediately if you have chest pain, shortness of breath, or dizziness.

How do doctors diagnose arrhythmias?

To diagnose arrhythmia, your doctor will ask you about your symptoms, medical history, eating and exercise habits, and if you have a family history of arrhythmia. During a physical exam, you doctor will:

  • Listen to your heart
  • Check your pulse
  • Check for swelling in your lower extremities
  • Check for signs of thyroid disease and other conditions that can cause arrhythmia

Your doctor may also do an electrocardiogram (EKG or ECG)—the primary test for diagnosing arrhythmia. An EKG records your heart’s electrical activity, including your heart rate (if it is normal, fast or slow) and rhythm (if it is steady or irregular). Your doctor may perform the EKG while you are at rest or also do a stress test—an EKG while you are exercising on a treadmill to record your heart’s activity while it’s working hard.

Additional tests may be necessary to rule out other causes or to help your doctor decide on treatment. These include:

  • Blood tests to check for blood chemistry imbalances, such as hyperkalemia and others
  • Cardiac catheterization and imaging to look for signs of heart disease
  • Chest X-ray to see the condition of your heart and lungs and look for heart problems
  • Echocardiography (echo) to check the size and shape of your heart and how well it functions
  • Holter monitor, a type of EKG that you wear for a few days to continuously record your heart’s electrical activity during your normal activities

An accurate diagnosis will guide treatment decisions. Your doctor will recommend a treatment plan that is best for you based on your type of arrhythmia, age, medical history, and other factors.

What are the treatments for arrhythmias?

Arrhythmia treatment begins with seeking medical care from your healthcare provider and getting an accurate diagnosis. There are three main treatment goals: symptom relief, prevention of fatal circulatory collapse, and prevention of arrhythmia-related complications like stroke.

Cardiologists prescribe several classes of medications to prevent an arrhythmia from happening again or to keep your heart rate from becoming too fast or too slow. It is important to follow your treatment plan for arrhythmias precisely and to take all medicines as instructed to avoid recurrence or complications.

Medications for treatment of arrhythmia

Medications that can be effective in the treatment of arrhythmias include:

  • Amiodarone (Cordarone)
  • Diltiazem (Cardizem, Cartia)
  • Digoxin (Lanoxin)
  • Metoprolol (Lopressor, Toprol)
  • Procainamide (Pronestyl)
  • Sotalol (Betapace)
  • Verapamil (Calan, Covera)

Urgent treatment for serious arrhythmias

When arrhythmias are serious, you may need urgent treatment to restore a normal rhythm. This may include:

  • Cardiac ablation, a procedure used to destroy areas in your heart that may be causing your heart rhythm problems
  • Implantation of a cardiac defibrillator
  • Implantation of a temporary pacemaker to interrupt the arrhythmia
  • Medications given through a vein

What are the potential complications of arrhythmia?

You can help minimize your risk of serious complications by following the treatment plan you and your healthcare professional design specifically for you. Complications of arrhythmias include:

  • Congestive heart failure (deterioration of the heart’s ability to pump blood)
  • Heart attack (myocardial infarction)
  • Stroke
Was this helpful?
  1. Arrhythmia, American Heart Association.
  2. What Is an Arrhythmia? National Heart, Lung and Blood Institute.
  3. Heart disease. New York Online Access to Health.
  4. Kellerman RD, Raker DP (Eds.) Conn’s Current Therapy, 72d ed. Philadelphia: Elsevier, 2020.
  5. Domino FJ (Ed.) Five Minute Clinical Consult, 27th ed. Philadelphia: Wolters Kluwer, 2019.
  6. Symptoms, diagnosis and monitoring of arrhythmia. American Heart Association.
  7. What is an arrhythmia? National Heart, Lung, and Blood Institute Diseases and Conditions Index.
  8. Hatch F, Lancaster MK, Jones SA. Aging is a primary risk factor for cardiac arrhythmias: disruption of intracellular Ca2+ regulation as a key suspect. Expert Rev Cardiovasc Ther. 2011;9(8):1059-1067. doi:10.1586/erc.11.112. Retrieved from
  9. Spears DA, Gollob MH. Genetics of inherited primary arrhythmia disorders. Appl Clin Genet. 2015;8:215-233. Published 2015 Sep 18. doi:10.2147/TACG.S55762. Retrieved from
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Mar 11
View All Heart Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.