[1] Univ Michigan, Med Ctr, Sch Med, Dept Med,Div Cardiol, Ann Arbor, MI 48109 USA
[2] Hartford Hosp, Div Cardiol, Hartford, CT 06115 USA
[3] Emory Univ, Sch Med, Dept Med, Atlanta, GA USA
[4] Univ Hosp, Thoraxctr, Groningen, Netherlands
[5] Toronto Hosp, Dept Med, Toronto, ON M5T 2S8, Canada
[6] Queen Elizabeth 2 Hlth Sci Ctr, Div Cardiol, Halifax, NS, Canada
[7] Providence St Joseph Med Ctr, Los Angeles, CA USA
[8] Warner Lambert Parke Davis, Parke Davis Pharmaceut Res Div, Ann Arbor, MI USA