For life-threatening medical emergencies, call 911 without delay. For a mental health crisis, call or text 988 for free and confidential crisis support.
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:
June 24, 2023
Author: Healthwise Staff Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Clinical Review Board All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Healthwise is a URAC accredited health web site content provider. Privacy Policy.
How this information was developed to help you make better health decisions.