The aortic valve sits between the lower left chamber of your heart (left ventricle) and a major blood vessel (aorta). The aorta is the blood vessel that channels oxygen-rich blood from the heart to the rest of your body. The aortic valve acts like a gatekeeper. It opens to release blood from the left ventricle into the aorta and closes to keep any of the blood from washing backward.
Aortic valve regurgitation occurs when the valve doesn’t close tightly enough, and some blood leaks backward into the left ventricle, causing your heart to enlarge.