[1] Yonsei Univ, Coll Med, Div Cardiol, Yonsei Cardiovasc Ctr, Seoul 120752, South Korea
[2] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Div Cardiol, Boston, MA USA
[3] Nippon Med Sch, Div Cardiol, Tokyo 113, Japan
[4] Kawasaki Med Sch, Dept Cardiol, Kurashiki, Okayama, Japan