Under which of the following circumstances is medical management logical?

A. Moderate aortic insufficiency seen on echocardiography with normal left ventricular end-systolic dimensions

DISCUSSION: The left ventricle is usually able to compensate for a long time for the increased volume load imposed by aortic insufficiency. The natural history of asymptomatic aortic stenosis is excellent; 10-year survival for moderate aortic insufficiency managed medically is as high as 85% to 95%. Medical management typically consists of diuretics and afterload reduction; however, once the compensatory mechanisms begin to fail, survival is limited. Half of patients with signs or symptoms of congestive heart failure die within 2 years. Therefore, evidence of left ventricular dilation by echocardiography (left ventricular end-systolic dimension greater than 55 mm., cardiomegaly on chest roentgenography) or symptoms of congestive heart failure are indications for aortic valve replacement.