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.
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 may also be caused by some substances or drugs, including:
Sometimes medicines used to treat one type of arrhythmia will cause another type of abnormal heart rhythm.
Some of the more common abnormal heart rhythms are:
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 include:
The doctor will listen to your heart with a stethoscope and feel your pulse. Your blood pressure may be low or normal.
Heart monitoring devices are often used to identify the rhythm problem, such as a:
Other tests may be done to look at heart function:
A special test, called an electrophysiology study (EPS), is done to take a closer look at the heart's electrical system.
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 health care provider. Do not stop taking the medicine or change the dose without first talking to your health care provider.
Other treatments to prevent or treat abnormal heart rhythms include:
The outcome depends on several factors:
Call your health care provider if:
Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia.
Abnormal heart rhythms; Bradycardia; Tachycardia
Olgin SE. Approach to the patient with suspected arrhythmia. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 62.
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. J Am Coll Cardiol. 2012;60(14):1297-1313.
Rubart M, Zipes DP. Genesis of cardiac arrhythmias, electrophysiologic considerations. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 35.
Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
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