[1] Univ Calif San Diego, Div Cardiol, Sect Electrophysiol, San Diego, CA 92103 USA
[2] Univ Calif Davis, Div Cardiovasc Med, Sacramento, CA 95817 USA
[3] West Virginia Univ, Heart & Vasc Inst, Div Cardiovasc Med, Morgantown, WV 26506 USA
[4] Univ Oklahoma, Hlth Sci Ctr, Div Cardiol, Oklahoma City, OK USA
[5] Allegheny Gen Hosp, Dept Med, Pittsburgh, PA 15212 USA
[6] Oregon Hlth & Sci Univ, Div Cardiovasc Med, Portland, OR 97201 USA
[7] Univ Calif San Diego, 9452 Med Ctr Dr,MC7411, San Diego, CA 92037 USA