The Role of Serum Magnesium Levels in the Prevention and Management of Cardiac Arrhythmias

Abstract

Background and Purpose: Hypomagnesemia has been strongly implicated in the pathogenesis of cardiac arrhythmias due to its role in myocardial excitability and membrane stabilization. Serum magnesium acts as a natural calcium antagonist, and its deficiency promotes afterdepolarizations and increased automaticity in cardiac myocytes, predisposing to both atrial and ventricular arrhythmias. This abstract aims to summarize current evidence regarding the preventive and therapeutic significance of optimal magnesium levels in arrhythmia management.

 Methods: A synthesis of cross-sectional, cohort, and interventional studies published between 2008 and 2024 was performed. Data from community-based studies, including the Atherosclerosis Risk in Communities (ARIC) and the Chronic Renal Insufficiency Cohort (CRIC), were analyzed alongside randomized clinical trials evaluating magnesium supplementation in coronary artery bypass surgery and heart failure patients.

Results: Low serum magnesium levels (<0.75 mmol/L) were consistently associated with a higher risk of atrial fibrillation and premature ventricular contractions. Magnesium repletion reduced proarrhythmic risk in conditions such as acute myocardial infarction, heart failure, and postoperative cardiac surgery, though findings varied depending on baseline magnesium status and duration of supplementation. Meta-analyses indicated that maintaining magnesium within the mid-normal range was associated with reduced incidence of sudden cardiac death and arrhythmic events.

 Conclusions: Adequate serum magnesium levels play a protective role in cardiac electrophysiology and may serve as both a preventive and adjunctive therapeutic factor in arrhythmia management. While supplementation benefits specific high-risk populations, its preventive effects in the general population require further large-scale, randomized trials. Monitoring and correcting magnesium deficiency should therefore be an integral component of cardiovascular risk management.