[1] Katholieke Univ Leuven, Dept Rehabil Sci, Res Ctr Cardiovasc & Resp Rehabil, Louvain, Belgium
[2] Univ Hosp Gasthuisberg, Div Cardiol, B-3000 Louvain, Belgium
[3] Tech Univ Munich, Deutsch Herzzentrum Munchen, Dept Pediat Cardiol & Congenital Heart Dis, D-80290 Munich, Germany
[4] Great Ormond St Hosp Sick Children, Cardiac Unit, London WC1N 3JH, England