1. From the Cardiovascular Research (F.C.T., H.G., T.F.L.), Physiology Institute, University Zürich-Irchel; Division of Cardiology (F.C.T., T.F.L.), University Hospital, Zürich, Switzerland; Ophthalmology University Hospital (P.M., C.C.), Basel, Switzerland; and Division of Cardiology (E.G.N.), University of Michigan Medical Center, Ann Arbor, Mich.