1 Department of Cardiac Surgery, Feiring Heart Clinic, Feiring, Norway; Department of Cardiothoracic and Vascular Surgery, University Hospital of North Norway, 9038 Tromsø, Norway. Electronic address: sven.m.almdahl@unn.no.
2 Department of Cardiac Surgery, Feiring Heart Clinic, Feiring, Norway.
3 Department of Cardiology, Feiring Heart Clinic, Feiring, Norway.