1. From the Cardiology Section, Veterans Affairs Medical Center (L.B.), Bronx, NY; Cardiology Section, Veterans Affairs Medical Center (I.A., S.Z.), Minneapolis, Minn; Cardiology Section, Veterans Affairs Medical Center (I.S.C.), West Haven, Conn; and Cardiovascular Division, Department of Medicine, University of Minnesota Medical School (D.J., J.N.C.), Minneapolis, Minn.