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Cardioversion: Electrical System of the Heart

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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. The fibers carry the signal and cause the lower chambers (ventricles) to contract.

The electrocardiogram (EKG, ECG) tracing above reflects this normal electrical activity.

ByHealthwise Staff
Primary Medical ReviewerRakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Specialist Medical ReviewerJohn M. Miller, MD, FACC - Cardiology, Electrophysiology
Last RevisedDecember 14, 2012

WebMD Medical Reference from Healthwise

Last Updated: December 14, 2012
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.

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