1. From the Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands (M.S., L.B.v.M., P.H., S.P., A.v.H., M.K., F.W.P.); and Division of Cardiology, Fondazione, Cardiocentro Ticino, Lugano, Switzerland (A.A.).