cardiovascular disorders
Aortic Regurgitation
Key Points
The primary causes of acute aortic regurgitation (AR) are infective endocarditis and dissection of the ascending aorta; chronic AR in adults is most often caused by degeneration of the aortic valve or root. Acute AR causes symptoms of heart failure and cardiogenic shock, but signs of AR may be absent. Chronic AR is typically asymptomatic for years followed by progressive exertional dyspnea, orthopnea, and paroxysmal nocturnal dyspnea. Typical heart sounds with chronic AR include a normal first heart sound (S1) followed by a sharp or slapping second heart sound (S2) and a blowing, high-pitched, decrescendo diastolic murmur. Acute AR requires prompt aortic valve replacement or repair. Chronic AR requires aortic valve replacement or repair when symptoms or left ventricular dysfunction develops; patients who meet criteria but are not candidates for surgery benefit from treatment of heart failure. AR is sometimes accompanied by a dilated ascending aorta. Indications for surgery on the ascending aorta may occur before surgery is indicated for AR. 