Aortic valve regurgitation is the backflow of blood from the aorta through the aortic valve into the left ventricle. If enough blood flows back into the heart, it can increase the workload on the left ventricle (lower left chamber), causing damage.

When the heart pumps, the aortic valve opens to let oxygen-rich blood flow from the left ventricle into the aorta. When the heart rests between beats, the aortic valve closes to keep blood from flowing backward into the heart. In aortic valve regurgitation, the aortic valve does not close properly. With each heartbeat, some of the blood pumped into the aorta leaks back (regurgitates) through the faulty valve into the left ventricle.