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…

Electrical System of the Heart

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

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

Current as ofApril 9, 2019

Author: Healthwise Staff
Rakesh K. Pai, MD - Cardiology, Electrophysiology
E. Gregory Thompson, MD - Internal Medicine
Martin J. Gabica, MD - Family Medicine
Adam Husney, MD - Family Medicine
John M. Miller, MD, FACC - Cardiology, Electrophysiology

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