The Role of High-Normal Potassium Levels in the Maintenance of Sinus Rhythm Following Cardiac Surgery in Patients with Persistent Atrial Fibrillation.

Abstract

Highlights: Potassium Optimization: Maintaining high-normal potassium levels (>4.4 mmol/L) during and after bypass significantly improves the restoration and maintenance of sinus rhythm.High Success Rates: 87% of patients achieved sinus rhythm post-surgery, with 71% remaining stable at 48 hours.Predictors of Failure: A larger left atrial diameter was identified as a primary reason for failed cardioversion and AF recurrence.Improved Recovery: Restoring sinus rhythm led to better hemodynamic stability and significantly reduced the duration of ICU stays.

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.