Background: One of the most difficult issues in the care of asymptomatic patients with severe valvular heart disease, particularly mitral regurgitation, is the timing of the surgical intervention. Unlike the stenotic lesions, regurgitant lesions often progress insidiously, causing left ventricular damage before symptoms develop. Current criteria for surgical intervention include left ventricular dimensions and left ventricular ejection fraction. The clinical problem is that once these morphologic criteria are fulfilled, the prognosis has already worsened, even if surgery is performed promptly. In addition, the onset of symptoms may be difficult to detect because of physical inactivity or under-reporting. In some patients, it may be unclear whether symptoms are related to valvular heart disease or other conditions.