[1] Univ Pittsburgh, Med Ctr, Heart & Vasc Inst, Pittsburgh, PA USA
[2] Univ Utah, Div Cardiovasc Med, Salt Lake City, UT USA
[3] Ascension St Vincents Med Ctr, Cardiol Dept, Jacksonville, FL USA
[4] Adventist Hlth, Cardiol Dept, Portland, OR USA
[5] Univ Pittsburgh, Heart & Vasc Inst, Med Ctr, 200 Lothrop St,South Tower,3rd Floor,Room E325 5, Pittsburgh, PA 15213 USA