The two valves on the left side of the heart (mitral and aortic) were most commonly affected, allowing blood to leak backward after the valve should have closed completely (regurgitation). On the first echocardiogram, 38 patients had abnormal mitral valve function; on the follow-up echocardiogram, valve function was unchanged in 19 patients, had improved in 17 patients, and had worsened in 2 patients. Among the 43 patients with aortic valve abnormality on the first echocardiogram, this abnormality remained unchanged in 22 patients, had improved in 19 patients, and had worsened in 2 patients. The two valves on the right side of the heart (tricuspid and pulmonic) were less commonly affected. Tricuspid abnormality was found initially in 29 patients; during follow-up, 9 patients had no change, 18 had improved, and 1 had worsened. Pulmonic abnormality was found initially in 11 patients; 1 had no change and 9 improved during follow-up.