Aortic Regurgitation (Aortic Insufficiency) By Guy P Armstrong, MD, Waitemata District Health Board and Waitemata Cardiology, Auckland Reviewed / Revised Jul 2022 | Modified Sep 2022 View Patient Education Etiology Pathophysiology Symptoms and Signs Diagnosis Prognosis Treatment Key Points Topic Resources Aortic Regurgitation Austin Flint Murmur Aortic Regurgitation Aortic regurgitation (AR) is incompetency of the aortic valve causing backflow from the aorta into the left ventricle during diastole.