Aortic Regurgitation ( Acute and chronic ) - Usmle step 1 cardiovascular physiology Aortic insufficiency (AI), also known as aortic regurgitation (AR), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a consequence, the cardiac muscle is forced to work harder than normal As chronic aortic regurgitation develops slowly over time, the left ventricle slowly and easily compensate