The heart's conduction system also is called the heart's electrical signaling system. Electrical signals start in a group of cells at the top of the heart called the sinus node. The signals tell the heart to beat. The sinus node also is called the heart's natural pacemaker. It can become weak as a person gets older.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.
Benefactor support fuels Mayo Clinic’s groundbreaking research. Make a gift today to help us save lives.