1. From the Division of Cardiovascular Pathophysiology (J.D., B.L., A.G.), School of Medicine, and the Department of Cardiology and Cardiovascular Surgery (J.D.), University Clinic, University of Navarra, Pamplona; the Division of Cardiology (R.Q.), Donostia Hospital, San Sebastián; and the Division of Hemodynamics (M.L., J.L.M.U.), Guipuzcoa Policlinics, San Sebastián, Spain.