Serum Magnesium Levels and QTc Interval Prolongation As Prognostic Markers in Acute Myocardial Infarction: A Randomized Controlled Study.

ABSTRACT

Introduction Acute myocardial infarction (AMI) is frequently preceded by arrhythmias, which continue to be a prominent cause of abrupt fatality in AMI. Abnormal magnesium levels have been linked to the emergence of arrhythmia because it enhances myocardial metabolism and cardiac output and prevents calcium buildup and myocardial cell death by lowering arrhythmias. The objectives of this study were to evaluate serum magnesium levels and QTc interval as prognostic indicators in AMI patients during the initial 48 hours of hospital stay and to correlate these parameters with the Global Registry of Acute Coronary Events (GRACE) scoring. We studied AMI patients by dividing them into two groups those with abnormal and those with normal serum magnesium levels. Methods After obtaining ethical approvals, patients were subjected to detailed history, which included sociodemographic details, drug history, clinical examination, and investigations such as creatine kinase myocardial band (CK-MB), CK-total, troponin-T, ECG (QTc interval), two-dimensional echocardiogram (2D-ECHO), serum creatinine and magnesium levels, heart rate, and blood pressure. We also calculated the GRACE score for all patients. Results We found that patients in the age group of 51-60 years were more prone to developing arrhythmias, and while AMI was more prevalent in males, the occurrence of arrhythmias was slightly higher in females with AMI. Anterior wall motion abnormality (AWMA) was the most predominant abnormality, and 12.3% of AWMA patients had arrhythmias. QTc interval was significantly longer in patients who developed arrhythmias. Interestingly, among patients with QTc prolongation, 35% patients had abnormal magnesium levels, while 65% had normal magnesium levels. In our study, of the 25 patients with hypermagnesemia, nine (36%) developed arrhythmias, while of the 75 patients with hypomagnesemia, 15 (20%) patients developed arrhythmias. Interestingly, we found that there was a positive correlation between GRACE score and serum magnesium as well as QTc interval prolongation. Lastly, among the six deaths reported, three (50%) patients had arrhythmias. Conclusion Overall, we conclude that serum magnesium levels play a pivotal role as a prognostic tool for arrhythmias and are a useful investigation during the initial 48 hours of admission in AMI patients.