[1] Univ Florida, Div Cardiovasc Med, Gainesville, FL USA
[2] Maine Med Ctr, Div Cardiovasc Med, Portland, ME USA
[3] Univ Florida, Dept Internal Med, Gainesville, FL USA
[4] Baylor Coll Med, Div Cardiovasc Med, Houston, TX USA
[5] Univ Kentucky, Gill Heart Inst, Div Cardiovasc Med, Lexington, KY USA
[6] Univ Florida, Div Cardiovasc Med, 1600 SW Archer Rd,POB 100277, Gainesville, FL 32610 USA