What is a heart beat made of?

A heartbeat is made up of the rhythmic contraction and relaxation of the heart muscle, primarily the atria and ventricles, driven by electrical impulses generated by the sinoatrial (SA) node. This electrical activity causes the heart to pump blood throughout the body, delivering oxygen and nutrients while removing waste products. The heartbeat can be measured in beats per minute (BPM) and is influenced by various factors, including physical activity, emotional state, and overall health.