[1] St Bartholomews Hosp, Echocardiog Lab, Barts Heart Ctr, London, England
[2] St Bartholomews Hosp, Electrophysiol Dept, Barts Heart Ctr, London, England
[3] UCL, Inst Cardiovasc Sci, London, England
[4] Athens Univ, Hippokration Hosp, Med Sch, Cardiol Dept 1, Athens, Greece