OBJECTIVE: To study the effectiveness of magnesium in cardioplegic solution in preventing postoperative arrhythmias and perioperative ischemia. DESIGN: Randomized, control study. SETTING: The cardiovascular surgery divisionof a major referral centre for the maritime provinces of Canada. PATIENTS: Fifty patients scheduled to undergo coronary artery bypass who had a normal ejection fraction, normal preoperative serum magnesium level and no history of atrial or ventricular arrhythmia were randomized into two groups of 25 patients. One group received magnesium sulfate (15 mmol/L) in the cardioplegic solution (group 1), the other (control) group did not receive magnesium sulfate in the cardioplegic solution (group 2). INTERVENTION: Coronary artery bypass grafting during which myocardial protection was provided by intermittent cold blood cardioplegia. OUTCOME MEASURES: Postoperative serum magnesium levels, cardiac-related death, infarction and arrhythmias. RESULTS: All group 2 patients had a lower postoperative serum magnesium level than group 1 patients. There were no cardiac-related deaths in either group. More group 2 patients had ischemic electrocardiographic changes than group 1 patients (p < 0.03). Non-Q wave myocardial infarction occurred in two patients (one in each group). Eight patients in group 2 had atrial fibrillation compared with five patients in group 1. Ventricular ectopia occurred significantly (p < 0.01) more frequently in group 2 than in group 1. CONCLUSION: The addition of magnesium to the cardioplegic solution is beneficial in reducing the incidence of perioperative ischemia and ventricular arrhythmia in patients who undergo coronary bypass grafting.
RCT Entities:
OBJECTIVE: To study the effectiveness of magnesium in cardioplegic solution in preventing postoperative arrhythmias and perioperative ischemia. DESIGN: Randomized, control study. SETTING: The cardiovascular surgery division of a major referral centre for the maritime provinces of Canada. PATIENTS: Fifty patients scheduled to undergo coronary artery bypass who had a normal ejection fraction, normal preoperative serum magnesium level and no history of atrial or ventricular arrhythmia were randomized into two groups of 25 patients. One group received magnesium sulfate (15 mmol/L) in the cardioplegic solution (group 1), the other (control) group did not receive magnesium sulfate in the cardioplegic solution (group 2). INTERVENTION: Coronary artery bypass grafting during which myocardial protection was provided by intermittent cold blood cardioplegia. OUTCOME MEASURES: Postoperative serum magnesium levels, cardiac-related death, infarction and arrhythmias. RESULTS: All group 2 patients had a lower postoperative serum magnesium level than group 1 patients. There were no cardiac-related deaths in either group. More group 2 patients had ischemic electrocardiographic changes than group 1 patients (p < 0.03). Non-Q wave myocardial infarction occurred in two patients (one in each group). Eight patients in group 2 had atrial fibrillation compared with five patients in group 1. Ventricular ectopia occurred significantly (p < 0.01) more frequently in group 2 than in group 1. CONCLUSION: The addition of magnesium to the cardioplegic solution is beneficial in reducing the incidence of perioperative ischemia and ventricular arrhythmia in patients who undergo coronary bypass grafting.