1. From the Department of Internal Medicine and Botnar Center for Extreme Medicine, University Hospital, Lausanne, Switzerland (P.-Y.J., E.R., S.T., M.S., P.T., C.S.-C., P.N., U.S., C.S.); Swiss Cardiovascular Center Bern, University Hospital, Bern, Switzerland (S.F.R., T.S., D.H., Y.A.); and Instituto Boliviano de Biologia de Altura, La Paz, Bolivia (C.S.S., M.V.).