Electrical System of the Heart

Electrical System of the Heart

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 of: December 15, 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