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What triggers a heart beat?

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Your heartbeat is triggered by electrical impulses that travel down a special pathway through your heart. Here's how that happens:

  • The impulse starts in a small bundle of specialized cells called the SA node (sinoatrial node), located in the right atrium. This node is known as the heart's natural pacemaker. The electrical activity spreads through the walls of the atria and causes them to contract.
  • A cluster of cells in the center of the heart between the atria and ventricles, the AV node (atrioventricular node) is 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.
  • The His-Purkinje network is a pathway of fibers that sends the electrical impulse from the AV node to the muscular walls of the ventricles, causing them to contract.

From: How Your Heart Works WebMD Medical Reference

SOURCE: National Heart Blood Lung Institute, National Institutes of Health.

Reviewed by James Beckerman on November 08, 2017

SOURCE: National Heart Blood Lung Institute, National Institutes of Health.

Reviewed by James Beckerman on November 08, 2017

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