Atrial fibrillation (AF) is highly prevalent in patients undergoing cardiac surgery, and persistent AF poses significant challenges in postoperative rhythm management. This study investigated whether maintaining high-normal potassium levels (>4.4 mmol/L) during and after cardiopulmonary bypass (CPB) enhances SR restoration and stability in patients with persistent AF. A prospective observational study of 245 patients undergoing elective cardiac surgery was conducted, with potassium levels maintained above 4.5 mmol/L during CPB and supplemented postoperatively for 48 hours. Outcomes included SR conversion rates, hemodynamic parameters, and predictors of rhythm stability. Results showed that 87% of patients reverted to SR post-CPB, with 71% maintaining SR at 48 hours. Higher intraoperative potassium levels (mean, 4.54 vs 4.41 mmol/L; P=.02) significantly predicted successful cardioversion, whereas larger left atrial diameter (67.2 vs 53.8 mm; P<.001) correlated with AF persistence. Hemodynamic stability improved in patients with SR, with lower heart rates, higher mean arterial pressures, and reduced ICU stays (52.5 vs 58.8 h; P<.001). The study concludes that maintaining high-normal potassium levels during and after CPB facilitates SR restoration and short-term stability in patients with persistent AF, improving hemodynamics and reducing ICU dependency. Left atrial enlargement remains a key determinant of AF recurrence. These findings support perioperative potassium optimization as a feasible strategy to enhance postoperative outcomes, warranting further multicenter trials for validation
