1. From the Heart and Circulation Center (E.M.), Dresden, Germany; University Hospital (D.P., L.E.), Leipzig, Germany; Hannover Medical School (J.T.), Hannover, Germany; Guidant Corp (B.S., S.H.), Cardiac Rhythm Management Division, European Research Department, Brussels, Belgium; and Humboldt University and German Heart Institute (E.F., C.B.), Berlin, Germany.