[1] Univ Oslo, Rikshosp, Oslo Univ Hosp, Dept Cardiol, N-0027 Oslo, Norway
[2] Univ Oslo, Rikshosp, Oslo Univ Hosp, Dept Anaesthesiol, N-0027 Oslo, Norway
[3] Univ Oslo, Rikshosp, Oslo Univ Hosp, Genet Inst, N-0027 Oslo, Norway
[4] Univ Oslo, Rikshosp, Oslo Univ Hosp, Dept Med Genet, N-0027 Oslo, Norway