The Significant Decrease of Serum Sodium and Blood Pressure following Thoracoscopic Left Atrial Appendage Clipping

Abstract

Background: The epicardial left atrial appendage (LAA) closure may induce unwanted natriuretic peptides caused by the isolation of the LAA from circulation. Thus, this study aims to explore the possible change of blood pressure and electrolytes following the procedure. Methods: This was a retrospective, observational study including 52 atrial fibrillation (AF) patients with a history of thrombolic stroke who underwent thoracoscopic LAA clipping. Electrolytes, blood pressure, and brain natriuretic peptide were measured before the procedure, immediately after the device release, on the 1st day, the 2nd day postoperation, and discharge. Results: Thirty-five (66.04%) patients’ serum sodium level decreased by more than 4 mmol/L during 48 h postoperation. The systolic blood pressure at discharge was significantly lower than the baseline level (118.99 ± 12.29 mmHg vs. 122.93 ± 13.82 mmHg, p = 0.034), while the diastolic blood pressure was not significantly different to the baseline (78.00 ± 7.39 mmHg vs. 77.22 ± 7.72 mmHg, p = 0.502). A significant increase in brain natriuretic peptide was observed postoperatively, although it showed a trend of decline at discharge. Conclusion: Epicardial LAA clipping could induce an acute decrease in serum sodium postoperation, which indicates to the surgeons that the postoperative intake fluid amounts and serum sodium level management should be more appropriate. The decrease in systolic blood pressure indicates the possibility of expanding the benefits that patients received from LAA clipping, though further studies are needed to determine if this phenomenon is persistent in the long-term follow-up.