How the heart works

The heart is critical to our lives. It is a pump that delivers blood together with life-maintaining nutrients to all parts of our bodies. Just as with other pumps often used in daily life, the heart's continual function may require repair.

The heart consists of four chambers (two atria and two ventricles) that beat regularly to push blood through the body and lungs. The flow of blood into and out of these chambers is regulated by four heart valves: two of the valves are located between the upper (atrial) and lower (ventricular) chambers, and two are located between the ventricles (lower chambers) and arteries (vessels that carry blood away from the heart).

These valves open and close to regulate blood flow, opening to allow forward blood flow and closing to prevent backward blood flow. Without these valves working properly, the heart could not work effectively.