[1] Duke Univ, Sch Med, Duke Heart Ctr, Div Cardiol, Durham, NC USA
[2] Univ Alberta, Mazankowski Alberta Heart Inst, Canadian VIGOUR Ctr, Div Cardiol, Edmonton, AB, Canada
[3] Ronald Reagan UCLA Med Ctr, Ahmanson UCLA Cardiomyopathy Ctr, Los Angeles, CA USA
[4] SUNY Stony Brook, Dept Med, Div Cardiol, Stony Brook, NY USA