Change of schedule

Incomplete recovery from ischemia causes stunned myocardium. Ischemia may be due to coronary artery disease or aortic cross-clamping during surgery. Stunning leads to myocardial dysfunction. It has been suggested that the mechanism responsible for the contractile depression in stunned myocardium is a decreased sensitivity of the myofibrils to calcium. Levosimendan is a calcium sensitizer, which has been shown to improve the function of stunned myocardium without obvious impairment of diastolic function. Systemic vasodilation and need of vasoconstrictive medication is usually apparent after administration of levosimendan. Colucci et al have demonstrated that with intracoronary administration of milrinone, another inodilator, systemic vasodilation could be excluded. If this is true with levosimendan, it may be possible to improve left ventricular hypo/dyskinesia without afterload reduction by adding levosimendan into cardioplegia solution.

The investigators hypotize that levosimendan, delivered together with cardioplegia, can improve LV dysfunction after opening of aortic cross-clamp in patients undergoing aortic valve and coronary artery bypass operation. Our primary endpoint is a change in cardiac output 15 min after separation from cardiopulmonary bypass compared to the baseline. Secondary endpoints are a change in LV ejection fraction from baseline to 5 min after sternal closure and cTnT/CK-MB on the first postoperative morning.

Inclusion Criteria:

• preoperative LVEF 40% or less
• septal wall thickness more than 11mm
• less than moderate aortic insufficiency
• sinus rhythm before CPB

Exclusion Criteria:

• oesophageal disease
• known allergy to levosimendan or its metabolites or adjuvants.