Adenosine Cardioplegia; Improved Cardioprotection?

60 elective patients for CABG will be included to receive either standard hyperkalemic cardioplegia (St.Thomas Hospital Solution No I) or cardioplegia where supranormal potassium is replaced with 1.2 mM adenosine. Hypothesis as follows: 1. Adenosine instead of supranormal potassium in the cardioplegic solution give satisfactory cardiac arrest. 2. Adenosine instead of supranormal potassium in the cardioplegic solution gives equal cardioprotection. The patients will be followed with PiCCO-catheter to monitor cardiac function and repetitive blood samples to measure release of cardiac enzymes.