Comparative Evaluation of Dexmedetomidine and Magnesium Sulfate for Prevention of Postoperative Atrial Fibrillation in Patients of Coronary Artery Bypass Surgeries.

Introduction The main goal of this study is to compare the effects of dexmedetomidine and magnesium sulfate on preventing atrial fibrillation (AF) after off-pump coronary artery bypass graft (CABG) surgeries. AF is a type of irregular heartbeat that often occurs after heart surgery and can cause serious complications. We want to see which drug is more effective in reducing the risk of AF in patients who have had CABG surgeries without using a heart-lung machine.  Materials and methods This was a randomized clinical study, conducted on patients of ASA classes III and IV who were the candidates for off-pump coronary artery bypass graft surgeries, which were conducted in the cardiac operating room from the period October 2020 to April 2021, at the Department of Anaesthesia, Jawaharlal Nehru Medical College, Sawangi, Meghe. All patients were aged between 30 and 85 years and with a left ventricular ejection fraction of above 40%. Results When the two groups were compared, the incidence of arrhythmias was more in group D (a group that received injection dexmedetomidine infusion), predominantly AF with an incidence of 50% more as compared to group M (a group that received injection magnesium sulfate infusion). When hemodynamic parameters were compared, events of bradycardia and hypotension were significantly higher in group D as compared to group M. The heart rate (HR), when compared between the two groups intraoperatively from the duration before induction of anesthesia till during sternum closure, has a significant p-value (0.0001). Similarly, when the mean arterial pressure (MAP) was compared between the two groups intraoperatively, significant hypotension was noted in group D (p-value = 0.0001). Postoperatively, in the intensive care unit when the HR and MAP were compared for 48 hours, bradycardia and hypotension were noted, but drastic changes in the mean values of the HR and MAP were not seen in both groups D and M. Conclusion When comparing the antiarrhythmic properties of the study drugs, it was observed that intraoperative and postoperative arrhythmias were less with magnesium sulfate as compared with dexmedetomidine. It was also found that there were higher events of hypotension and bradycardia in the dexmedetomidine group as compared to the magnesium sulfate group.