1. From the Division of Cardiology, McGill University Health Centre, Montreal, Quebec, Canada (Z.Y., J.G., P-O.B., A.H., A.G.S.); GlaxoSmithKline Beecham, PA (D.J.B.); and Institute of Pharmacology, University of Sherbrooke, Sherbrooke, Quebec, Canada (P.D.O-J.).