[1] Menzies Sch Hlth Res, Darwin, NT, Australia
[2] Aswan Heart Ctr, Dept Cardiol, Aswan, Egypt
[3] Univ N Carolina, Heart & Vasc Ctr, Chapel Hill, NC USA
[4] Univ London Imperial Coll Sci Technol & Med, Cardiothorac Surg, London, England
[5] Mayo Clin, Dept Cardiol, Rochester, MN 55905 USA