Appointments

800.659.7822

Request an Appointment

Questions

800.659.7822

Contact us with Questions

Expand Content

Heart Beat

How does the heart beat?

The atria and ventricles work together, alternately contracting and relaxing to pump blood through your heart. The electrical system of your heart is the power source that makes this possible.

Your heartbeat is triggered by electrical impulses that travel down a special pathway through your heart.

  • SA node (sinoatrial node) - known as the heart's natural pacemaker
    The impulse starts in a small bundle of specialized cells located in the right atrium, called the SA node. The electrical activity spreads through the walls of the atria and causes them to contract.
  • AV node (atrioventricular node)
    The AV node is a cluster of cells in the center of the heart between the atria and ventricles, and acts like a gate that slows the electrical signal before it enters the ventricles. This delay gives the atria time to contract before the ventricles do.
  • His-Purkinje Network
    This pathway of fibers sends the impulse to the muscular walls of the ventricles and causes them to contract.

At rest, a normal heart beats around 50 to 99 times a minute. Exercise, emotions, fever and some medications can cause your heart to beat faster, sometimes to well over 100 beats per minute.

Print out a diagram of the Electrical System of the Heart. Adobe Acrobat is needed to view this file. Download a free version of Adobe Acrobat.*

Talk to a Nurse: Mon. - Fri., 8:30 a.m. - 4 p.m. (ET)

Call a Heart & Vascular Nurse locally 216.445.9288 or toll-free 866.289.6911.

Schedule an Appointment

Toll-free 800.659.7822

This information is provided by Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition.

© Copyright 2014 Cleveland Clinic. All rights reserved.

HealthHub from Cleveland Clinic

Read the Latest from Our Experts About cctopics » Heart & Vascular Health
Low-Carb Eating May Be Best for Weight Loss, Heart Health
11/25/14 6:00 a.m.
If you’re looking for a heart-healthy weight-loss diet to try, it appears that low-carbohydrate might be more effective than low-fat. A recent study found that a low-carb d...
by Heart & Vascular Team
Thanksgiving Dinner: Serve This, Not That (Infographic)
11/24/14 10:05 a.m.
Thanksgiving dinner is the ultimate family feast. Overeating turkey, stuffing, mashed potatoes and gravy, glaze...
High Blood Pressure? Don’t Take Vitamin D for It (Video)
11/20/14 8:31 a.m.
Sellers of vitamin D claim the nutrient can lower your blood pressure. But don’t believe the hype. Despite clai...
When Your Heart Stents Narrow, Brachytherapy Can Help
11/19/14 8:22 a.m.
Cardiac stents are an effective, nonsurgical way of holding a narrowed or blocked artery open to increase blood...
A Post ER Follow-Up Could Save Your Life
11/17/14 8:39 a.m.
Even if Emergency Room doctors say you didn’t actually have a heart attack, that doesn’t mean you h...