aortic regurgitation

Picture a swing door that no longer latches shut: every time you push water out through it, some sloshes straight back in. In aortic regurgitation the aortic valve fails to close completely during diastole, so a portion of the blood just ejected into the aorta leaks backward into the left ventricle.

Because the ventricle now receives blood from both the left atrium (normally) and from the leaking aorta (abnormally), it must handle an extra volume of blood with each beat. To cope, it dilates and enlarges. This volume overload can be tolerated for years, but a chronically overstretched ventricle eventually weakens, while sudden severe leakage — for example after infection or aortic dissection — can cause rapid, dangerous decompensation.

Causes include valve damage from infection, rheumatic disease, or congenital abnormality, and disease of the aortic root that stretches the valve open. On examination there may be a soft, blowing early-diastolic murmur and a bounding, collapsing pulse with a wide pulse pressure. Echocardiography quantifies the leak, and severe symptomatic regurgitation or progressive ventricular enlargement points toward valve surgery.

Acute and chronic forms behave very differently; this entry describes general principles rather than guiding any individual's care.