1. From the Department of Pharmacology (E.Q., T.B., C.N., K.A.K., G.Ø.A., J.-B.O., F.O.L., T.S.), the Center for Heart Failure Research (E.Q., I.S., T.B., C.N., F.S., J.A.K.B., K.A.K., G.Ø.A., O.M.S., J.B.O., F.O.L., T.S.), and the Institute for Experimental Medical Research (I.S., F.S., J.A.K.B., O.M.S.), University of Oslo, Norway; and the Department of Cardiology (I.S., G.Ø.A.), Ullevaal University Hospital, Oslo, Norway.