[1] Univ Bergen, Inst Med, N-5021 Bergen, Norway
[2] Haukeland Hosp, Dept Heart Dis, N-5021 Bergen, Norway
[3] Skellefteaa Hosp, Dept Med, Skelleftea, Sweden
[4] Herz Zentrum Bad Krozingen, Bad Krozingen, Germany
[5] Stavanger Univ Hosp, Dept Cardiol, Stavanger, Norway
[6] Aker Univ Hosp, Div Cardiol, Oslo, Norway