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Cardioversion: Electrical System of the Heart

In the normal heart, electrical impulses pace the rhythm at which the heart contracts and relaxes. The sinoatrial (SA) node triggers the electrical impulse, causing the upper chambers (atria) to contract. The signal travels through the atrioventricular (AV) node to the atrioventricular bundle, which divides into the Purkinje fibers that carry the signal and cause the lower chambers (ventricles) to contract. The electrocardiogram (EKG, ECG) tracing above reflects this normal electrical activity.

By	Healthwise Staff
Primary Medical Reviewer	E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer	John M. Miller, MD - Electrophysiology
Last Revised	November 2, 2010

WebMD Medical Reference from Healthwise

Last Updated: November 02, 2010

This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.