A backward flow of blood caused by a malfunctioning aortic valve.
Reflux of blood from the aorta into the left ventricle during diastole. Aortic regurgitation most commonly follows scarring of the aortic valve as a result of previous acute rheumatic fever, but it may also result from other conditions, such as syphilis or dissecting aneurysm. Mild cases are symptom-free, but patients more severely affected develop breathlessness, angina pectoris, and enlargement of the heart; all have a diastolic murmur. A badly affected valve may be replaced surgically with a prosthesis.