Irregular Heartbeat

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

What is an irregular heartbeat?

An irregular heartbeat is an arrhythmia. Arrhythmias include disorders of heart rate or heart rhythm. This includes an abnormally fast heart rate (tachycardia), a slow or low heartbeat (bradycardia), or an erratic heartbeat. An irregular heartbeat can cause symptoms involving the heart and lungs.

The cause of an irregular heartbeat is a problem with the heart’s electrical conduction system. In many cases, an irregular heartbeat is harmless. However, there are certain irregular heartbeats that can be serious or even life threatening. They can prevent the heart from effectively pumping enough blood to the body. Lack of adequate blood flow can damage organs, such as the brain.

Some people with an irregular heartbeat do not have any symptoms at all. Others may have only brief and occasional symptoms. Still others may have severe symptoms, which can lead to a life-threatening situation. Fortunately, doctors can usually treat arrhythmias successfully.

Left untreated, an irregular heartbeat can cause chest pain, heart attack, heart failure, or stroke. Seek immediate medical care (call 911) for serious symptoms including:

Seek prompt medical care if you under a doctor’s care for an irregular heartbeat and have persistent or recurrent symptoms, such as fatigue or palpitations.

What other symptoms might occur with irregular heartbeat?

Arrhythmias can cause a wide variety of symptoms. They can vary from person to person and in intensity.

Heart-related symptoms that may occur along with an irregular heartbeat

Common heart-related symptoms that may accompany an irregular heartbeat include:

  • Awareness of your heartbeat

  • Heart palpitations or feeling your heart flutter

  • Single skipped heartbeat or heartbeats that occur in rapid succession

  • High heart rate of more than 100 beats per minute, also called max heart rate

  • Slow heart rate of less than 60 beats per minute

Other symptoms that may occur along with an irregular heartbeat

It is possible for an irregular heartbeat to last long enough to affect the heart’s ability to work efficiently. When this happens, serious symptoms can include:

  • Chest pain

  • Dizziness, lightheadedness, or near fainting

  • Fatigue

  • Skin paleness

  • Shortness of breath or rapid breathing 

  • Rapid heart rate or a very slow heart rate

  • Skipping multiple heartbeats and other changes in the pattern of your pulse

  • Sweating

Symptoms that might indicate a life-threatening or serious condition

Some arrhythmias can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have life-threatening symptoms including:

What causes an irregular heartbeat?

Irregular heartbeats result from problems with the way electrical impulses travel through the heart. Your heart has a natural pacemaker. It’s an area of cells that send out electrical signals to control the heartbeat. There are also other areas of the heart that have the potential to send out signals. The heart rhythm can become irregular if there are problems with the normal pacemaker cells or other areas of the heart start to send signals. Irregular heartbeats can also occur when there is a problem with the heart muscle being able to transmit the signal.

Heart problems that can cause an irregular heartbeat

There are many possible problems that can occur in the heart’s electrical system. Examples include:

  • Atrial fibrillation or flutter, which is rapid heartbeats in the upper heart chambers

  • Heart block, which is a problem transmitting signals from the upper chambers to the lower chambers

  • Multifocal atrial tachycardia, which occurs when many different areas of the upper chambers try to send signals all at once

  • Paroxysmal supraventricular tachycardia, which is a rapid heart rate that comes and goes

  • Sick sinus syndrome, which is a group of heart rhythm problems that commonly affect older people

  • Ventricular fibrillation, which is a life-threatening condition that occurs when the lower chambers beat rapidly and uncontrollably. This prevents the heart from pumping blood.

  • Wolff-Parkinson-White syndrome, which is an abnormal electrical pathway connecting the upper and lower chambers

Risk factors for an irregular heartbeat

You are more likely to develop an irregular heartbeat if you have certain risk factors. However, not all people with risk factors will have problems. Risk factors include:

  • Blood chemistry imbalances, such as problems with your potassium level

  • Cardiomyopathy, which is a problem with or weakening of the heart muscle

  • Certain drugs or substances, such as amphetamines, cocaine, caffeine, nicotine, and some prescription medicines

  • Congestive heart failure

  • Hyperthyroidism, which is an overactive thyroid gland

  • Previous heart attack

What are the potential complications of an irregular heartbeat?

Complications of an irregular heartbeat can be life threatening in some cases. This includes heart attack, stroke, and congestive heart failure. You can reduce your risk of having serious complications by following your treatment plan exactly as your doctor recommends.

Medications are the main treatment and there are several classes of anti-arrhythmia drugs. If you have side effects or continue to have symptoms, talk with your doctor. It may be possible to switch to another medicine and get better results. In some cases, your doctor may recommend a procedure to restore a normal heartbeat (cardioversion) or control your heartbeat (pacemaker or implantable defibrillator).

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Aug 21
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