Heart's Electrical System Symptoms & Causes

LIke ThisLIke ThisLIke ThisLIke ThisLIke This

Your heart’s electrical system controls the pumping of blood. Under normal circumstances, your child’s heart beats 60 to 140 times a minute.

The heart’s electrical system includes:

  • sinoatrial node
    • also known as the sinus node or SA node
    • located in the right atrium.
    • the heart’s natural pacemaker
  • atrioventricular node
    • also known as the AV node
    • located on the interatrial septum
  • bundle of His
    • also known as the AV bundle or atrioventricular bundle
    • located on the walls of your heart’s ventricles

How does the heart beat?

During a single heartbeat, your child’s heart’s chambers relax and contract to pump blood.

  • The sinoatrial node — or the “pacemaker” — sends an electrical stimulus to initiate pumping.
  • Right and left atria are stimulated first, then the right and left ventricles.
  • The impulse then travels to the atriventural node, through the His, and into the ventricles. His provides electrical stimuli to both ventricles.

Each contraction represents one heartbeat.

How does my child’s heart’s electrical system relate to arrhythmia?

Almost all heart tissue can start a heartbeat, or become the “pacemaker.’ An arrhythmia may occur when:

  • the Sinoatrial node develops an abnormal rate
  • the normal conduction pathway is interrupted
  • another part of the heart takes over as pacemaker
We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

Boston Children's Hospital
300 Longwood Avenue, Boston, MA 02115
For Patients: 617-355-6000
For Referring Providers: 844-BCH-PEDS | 844-224-7337