Atrial fibrillation after blood and crystalloid cardioplegia in CABG patients.

In an investigation of factors influencing the occurrence of supraventricular arrhythmias, ninety-eight patients were randomized to receive either cold blood (n = 49) or cold crystalloid (n = 49) cardioplegia during an elective coronary artery bypass grafting operation and were followed for seven days for the development of postoperative atrial fibrillation (AF). Twenty-one patients in the blood-cardioplegia group and nine in the crystalloid-cardioplegia group developed AF (p < 0.01). The patients who developed AF had smaller CK-MB enzyme leaks one hour after the operation (57 +/- 26 iu/L for AF vs 70 +/- 30 iu/L for normal rhythm, p < 0.05), and more often spontaneous beating after cross-clamp release (37% vs 15%, p < 0.05), which indicates that AF was not associated with poor ventricular myocardial protection or conduction system protection. The lesser amount of cardioprotective solution with AF patients (3551 +/- 1585 ml vs 4064 +/- 1562 ml, p < 0.05) and the time of onset of atrial fibrillation (4.0 +/- 1.8 postop. days) indicate that AF is probably caused at least partly by a reperfusion injury at the atrial level. The possibility of atrial fibrillation can be reduced by giving sufficient cardioplegia and giving beta-blocking medicine after the operation.