[1] Univ Iowa, Div Cardiol, Iowa City, IA USA
[2] Univ Iowa, Dept Internal Med, Div Gen Internal Med, Iowa City, IA 52242 USA
[3] Univ Missouri, Kansas City, MO 64110 USA
[4] St Lukes Hosp, Mid Amer Heart Inst, Kansas City, MO 64111 USA
[5] Univ Michigan, Div Cardiol, Ann Arbor, MI 48109 USA
[6] Univ Missouri, Div Cardiol, Kansas City, MO 64110 USA