Abnormal heart rhythms; Bradycardia; Tachycardia; Fibrillation
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:
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.
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 ECG will be the first test done.
Heart monitoring devices are often used to identify the rhythm problem, such as a:
An echocardiogram is often ordered to examine the size or structure of your heart.
Coronary angiography to see how blood flows through the arteries in your heart.
A special test, called an electrophysiology study (EPS), is done to take a closer look at the heart's electrical system.
The outcome depends on several factors:
Taking steps to prevent coronary artery disease may reduce your chance of developing an arrhythmia.
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:
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:
Call your provider if:
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. Heart Rhythm. 2017. S1547-5271(17)31249-3. PMID: 29097320
Olgin JE. Approach to the patient with suspected arrhythmia. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 62.
Tomaselli GF, Rubart M, Zipes DP. Mechanisms of cardiac arrhythmias. In: Zipes DP, Libby P, Bonow RO, Mann DL, Tomaselli GF, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia, PA: Elsevier; 2019:chap 34.
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
Review Date: 5/16/2018
Reviewed 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, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 9-1-1 for all medical emergencies. Links to other sites are provided for information only—they do not constitute endorsements of those other sites. © 1997-2010 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.