Was this helpful?

What are arrhythmias?

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 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. Some arrhythmias are life threatening, but fortunately, arrhythmia treatment is successful in most cases.

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 symptoms of arrhythmias?

Arrhythmias may produce a broad range of symptoms, from barely noticeable to life threatening. Arrhythmia symptoms can vary in intensity among individuals.

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:

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 brief moment
  • Difficulty breathing or rapid breathing
  • Dizziness
  • Fainting or change in level of consciousness or lethargy
  • Irregular heartbeat
  • Low blood pressure (hypotension)
  • Rapid heart rate (tachycardia)
  • Shortness of breath
  • 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 have the ability to 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.

Cardiac arrhythmias causes

Problems can occur anywhere along the nerve conduction system within the heart, causing various arrhythmias. There are many different electrical abnormalities of the heart. Examples include:

  • Atrial fibrillation or flutter (rapid beating of the upper chambers of the heart, or atria)

  • Heart block or atrioventricular block (problem in transmitting signals from the upper to the lower chambers)

  • Multifocal atrial tachycardia (condition in which different areas of the upper chambers of the heart attempt to signal at once)

  • Paroxysmal supraventricular tachycardia (rapid heart rate that comes and goes)

  • Sick sinus syndrome (group of different heart rhythm problems that is most common in older people)

  • Ventricular fibrillation (life-threatening condition in which the lower chambers of the heart beat rapidly and uncontrollably)

  • Ventricular tachycardia (fast heart rate that originates in the lower chambers, or ventricles)

  • Wolff-Parkinson-White syndrome (abnormal nerve conduction pathways from the upper to lower chambers of the heart)

What are the risk factors for arrhythmias?

A number of factors increase the risk of developing arrhythmias. Not all people with risk factors will get arrhythmias. Risk factors for arrhythmias include:

  • Blood chemistry imbalances, such as abnormal potassium levels

  • Cardiomyopathy (weakened or abnormal heart muscle and function)

  • Certain substances or drugs, including amphetamines, caffeine, cocaine, and some prescription medications

  • Congestive heart failure (deterioration of the heart’s ability to pump blood)

  • Hyperthyroidism (overactive thyroid)

  • Past heart attack


How are arrhythmias treated?

Arrhythmia treatment begins with seeking medical care from your health care provider. To determine if you have arrhythmias, your health care provider will conduct several diagnostic tests.

There are three main treatment goals: symptom relief, prevention of fatal circulatory collapse, and prevention of arrhythmia-related complications like stroke. Several classes of medications may be used 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 of the medicines as instructed to avoid recurrence or complications.

Medications for treatment of arrhythmias

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

  • Amiodarone (Cordarone)

  • Atenolol (Senormin, Tenormin)

  • 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

  • Electrical shock therapy (defibrillation or cardioversion)

  • 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 arrhythmias?

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

  • Chest pain or pressure

  • Congestive heart failure (deterioration of the heart’s ability to pump blood)

  • Heart attack (myocardial infarction)

  • Stroke

Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2018 Nov 12
  1. Bope ET, Kellerman RD (Eds.) Conn’s Current Therapy. Philadelphia: Saunders, 2012
  2. Domino FJ (Ed.) Five Minute Clinical Consult. Philadelphia: Lippincott Williams & Wilkins, 2013
  3. Symptoms, diagnosis and monitoring of arrhythmia. American Heart Association.   
  4. What is an arrhythmia? National Heart, Lung, and Blood Institute Diseases and Conditions Index.

Explore Heart Health
Recommended Reading
Health Spotlight
Next Up
Answers to Your Health Questions
Trending Videos