About the Heart --> Your Heart --> The Electricity of the Heart

The heart has four chambers that beat in an organized manner. This is controlled by an electrical impulse. A chamber of the heart contracts when an electrical impulse moves across it. The signal starts in the sinoatrial node (sometimes called the sinus node or SA node), an area of special cells located in the right atrium. A discharge from the sinus node causes the heart to beat at a given rate, usually around 60 to 80 times a minute. This rate can be caused to go up or down by emotions, hormones and metabolic factors. This way, the heart can meet the many demands of the body.