Aortic Regurgitation

Explore this overview of aortic regurgitation (AR).
March 3, 2021


Aortic regurgitation (AR) is a condition in which the aortic valve does not close properly, allowing blood to flow in the reverse direction from the aorta back into the left ventricle during diastole. The leakage may prevent the heart from efficiently pumping blood to the rest of the body, causing symptoms of fatigue and dyspnea. If AR becomes severe, surgery is often required to repair or replace the aortic valve.


Aortic regurgitation (AR) is mainly caused by aortic root dilation which is idiopathic in the majority of cases. Other causes of AR include increasing age, hypertension, infective endocarditis, aortic dissection, and Marfan syndrome. When the pressure in the left ventricle falls below the pressure in the aorta, blood flows backwards into the left ventricle preventing the aortic valve from closing completely. The backward flow causes volume overload of the left ventricle which can lead to left ventricular hypertrophy, increasing the risk of heart failure, arrhythmias, myocardial infarction, and stroke.


A high-pitched, decrescendo diastolic murmur best heard in the second intercostal space at the left sternal border. The murmur can radiate to the left sternal border which can suggest a primary valvular pathology, or to the right sternal edge which can suggest a primary aortic root pathology. A third heart sound (S3) may be present due to increased early diastolic filling into a dilated left ventricle. A fourth heart sound (S4) can be heard when left ventricular hypertrophy becomes severe and ventricular filling during diastole is limited. 


There are no specific changes on the ECG for Aortic regurgitation, but ECG patterns characteristic of left ventricular hypertrophy and left atrial enlargement may be present.