Although beta-blockers arewidely used to treat cardiovascular diseases, including atrial and ventricular arrhythmias, hypertension, and heart failure, the exactmechanism by which metoprolol reduces the incidence of atrial fibrillation (AF) remains unclear [15].Research suggests that metoprolol's antiarrhythmic effects may be attributed to its influence on the remodeling of connexin43 (Cx43), acrucial protein for intercellular electrical communication in the heart [45]. The gene discussed is GJA1; the disease is heart failure.