Arrhythmias


Definition

An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregularly.

An arrhythmia can be harmless, a sign of other heart problems, or an immediate danger to your health.

Alternative Names

Abnormal heart rhythms; Bradycardia; Tachycardia; Fibrillation

Causes

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Normally, your heart works as a pump that brings blood to the lungs and the rest of the body.

To help this happen, your heart has an electrical system that makes sure it contracts (squeezes) in an orderly way.

Arrhythmias are caused by problems with the heart's electrical conduction system.

Some common causes of abnormal heartbeats are:

Arrhythmias

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Arrhythmias

Arrhythmias may also be caused by some substances or drugs, including:

Some of the more common abnormal heart rhythms are:

Symptoms

When you have an arrhythmia, your heartbeat may be:

An arrhythmia may be present all of the time or it may come and go. You may or may not feel symptoms when the arrhythmia is present. Or, you may only notice symptoms when you are more active.

Symptoms can be very mild, or they may be severe or even life threatening.

Common symptoms that may occur when the arrhythmia is present could include:

Exams and Tests

The health care provider will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal or even high as a result of being uncomfortable.

An electrocardiogram (ECG) will be the first test done.

Heart monitoring devices are often used to identify the rhythm problem, such as a:

An echocardiogram is sometimes ordered to examine the size or structure of your heart.

In selected cases, coronary angiography may be performed to see how blood flows through the arteries in your heart.

A special test, called an electrophysiology study (EPS), is sometimes done to take a closer look at the heart's electrical system.

Treatment

When an arrhythmia is serious, you may need urgent treatment to restore a normal rhythm. This may include:

Sometimes, better treatment for your angina or heart failure will lower your chance of having an arrhythmia.

Medicines called anti-arrhythmic drugs may be used:

Some of these medicines can have side effects. Take them as prescribed by your provider. Do not stop taking the medicine or change the dose without first talking to your provider.

Other treatments to prevent or treat abnormal heart rhythms include:

Outlook (Prognosis)

The outcome depends on several factors:

When to Contact a Medical Professional

Contact your provider if:

Prevention

Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia.

References

Al-Khatib SM, Stevenson WG, Ackerman MJ, et al. 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Executive summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm. 2018;15(10):e190-e252. PMID: 29097320 pubmed.ncbi.nlm.nih.gov/29097320/.

Nattel S, Tomaselli GF. Mechanisms of cardiac arrhythmias. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 62.

Olgin JE. Approach to the patient with suspected arrhythmia. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 49.

Tracy CM, Epstein AE, Darbar D, et al. 2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2012;60(14):1297-1313. PMID: 22975230 pubmed.ncbi.nlm.nih.gov/22975230/.

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