GLP-1 Receptor Agonists and Risk of Cardiac Arrhythmias: A Multi-Cohort Analysis of Atrial Fibrillation and Bradycardia in Diabetic Patients

Background. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been a cornerstone of type 2 diabetes and obesity treatment but the impact on cardiac rhythm is still not clear. Due to hyperactivity of the heart during rest, an increased risk of tachyarrhythmia was a concern with GLP-1RAs, but more recent information indicates potential protection against atrial fibrillation (AF). There is little evidence to support bradycardia. This is a narrative review, summarizing available randomized, observational, genetic, and mechanistic evidence in the field of GLP-1RAs and arrhythmias in diabetes from 2023 to 2026. Methods. Searches were conducted in October 2026. The findings were presented by study design and the type of arrhythmia and published effects estimates were presented across without re-pooling. Results. Meta-analyses of trials of semaglutide show a reduction in AF (RR 0.58, 95% CI 0.40–0.85) while 30 trials of all GLP-1RAs did not show a significant difference (OR 0.94, 95% CI 0.86–1.04). The overall AF risk was not significantly different in a matched cohort of 80,948 pairs (OR 0.96), but was reduced with ≥5% weight loss (OR 0.83). A Mendelian randomization study indicated lower odds of AF (0.78) that was not independent of BMI or diabetes. This is because the increases in heart-rate are agent-dependent and result from a direct sinus node action, and trial data did not indicate more sinus node dysfunction. Conclusions. GLP-1RAs seem to be rhythm safe in diabetes, and may have a possibly weight-related decrease in AF. But the endpoints were not prespecified and some confounding; studies specifically designed for monitoring rhythms are required.