[1] Chulalongkorn Univ, Dept Med, Div Cardiol, Bangkok, Thailand
[2] Chulalongkorn Univ, King Chulalongkorn Mem Hosp, Ctr Excellence Arrhythmia Res, Div Cardiovasc Med,Cardiac Ctr,Fac Med, Bangkok, Thailand
[3] Mayo Clin, Coll Med, Dept Cardiovasc Med, Rochester, MN USA
[4] Harvard Med Sch, Massachusetts Gen Hosp, Div Cardiovasc Med, Boston, MA USA
[5] Univ Michigan, Frankel Cardiovasc Ctr, Div Cardiovasc Med, 1500 E Med Ctr Dr,SPS 5853, Ann Arbor, MI 48109 USA