[1] Ahepa Univ Hosp, Dept Cardiol, Thessaloniki, Greece
[2] Gen Hosp G Papanikolaou, Dept Cardiol, Thessaloniki, Greece
[3] Attikon Univ Hosp, Dept Cardiol, Athens, Greece
[4] Mitera Gen Hosp, Dept Congenital Heart Dis, Athens, Greece
[5] Tzaneio Gen Hosp Piraeus, Dept Cardiol, Athens, Greece
[6] Interbalkan Med Ctr, Dept Cardiol, Thessaloniki, Greece
[7] HCS, Athens, Greece
[8] Onassis Cardiac Surg Ctr, Dept Pediat Cardiol, Athens, Greece
[9] Onassis Cardiac Surg Ctr, Adult Congenital Heart Dis Dept, Athens, Greece