1. From the Division of Cardiology (B.A., H.L.D.), University of Vermont College of Medicine, Burlington, Vt; Section of Cardiology (W.D.P., D.M., J.R.), Dartmouth-Hitchcock Medical Center, Lebanon, NH; Division of Cardiology (P.V.), Eastern Maine Medical Center, Bangor, Me; Division of Cardiology (T.R.), Maine Medical Center, Portland, Me; Catholic Medical Center (M.H.), Manchester, NH; and Central Maine Medical Center (W.P.), Lewiston, Me.