[1] Harvard Univ, Brigham & Womens Hosp, Sch Med, Div Cardiovasc, Boston, MA 02115 USA
[2] Harvard Univ, Sch Med, Massachusetts Gen Hosp, Cardiovasc Res Ctr, Boston, MA 02114 USA
[3] Harvard Univ, Sch Med, Massachusetts Gen Hosp, Div Cardiol, Boston, MA 02114 USA
[4] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Wellman Ctr Photomed, Boston, MA USA