1. From the Divisions of Cardiology (Dae-Hee K., Y.-S.C., Y.J.K., S.-C.Y., J.-M.S., Duk-Hyun K., J.-K.S.) and Biostatistics (S.-C.Y.), Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea; and Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Mass (M.D.H., R.A.L.).