[1] Norwegian Univ Sci & Technol, Dept Cardiothorac Surg, N-7034 Trondheim, Norway
[2] Norwegian Univ Sci & Technol, Inst Circulat & Med Imaging, N-7034 Trondheim, Norway
[3] Norwegian Univ Sci & Technol, St Olavs Univ Hosp, Dept Anaesthesiol, N-7034 Trondheim, Norway