1. From Cardiovascular Research, Physiology Institute (G.G.C., J.S., A.A., N.S., J.B., U.S., K.S., C.M.M., T.F.L., F.C.T.) and Center for Integrative Human Physiology (G.G.C., J.S., A.A., K.S., C.M.M., T.F.L., F.C.T.), University of Zürich, Zürich, Switzerland; Cardiology (C.M.M., T.F.L., F.C.T.), Cardiovascular Center, University Hospital Zürich, Zürich, Switzerland; and Faculty of Medicine (Z.Y.), Physiology Institute, University of Fribourg, Fribourg, Switzerland.