Influence of blood electrolyte levels on the risk of atrial fibrillation after cardiac surgery

Aim. To analyze the relationship of low blood potassium concentration before surgery with the risk of postoperative atrial fibrillation (POAF).

Material and methods. Data were collected and analyzed from patients admitted to the intensive care unit after cardiac surgery between January 2023 and June 2023. During the study period, 691 patients were operated on. Of these, 96 (13,9%) patients developed POAF, which made up group A (mean age 68,3±10,0). Control group B of patients with sinus rhythm was formed using a random generator and consisted of 96 patients with a mean age of 63,5±8,3.

Results. The median time to onset of arrhythmia was 39,0 (29,2-51,0) hours. The blood potassium concentration one hour before surgery was significantly reduced in patients who developed arrhythmia compared with the control group (p<0,001) and averaged 3,4±0,4 mmol/L. To determine the sensitivity and specificity of the association of hypokalemia with POAF, we used a confirmatory statistical method, namely constructing ROC curves (AUC 0,640 (95% confidence interval: 0,562-0,718; p<0,001)).

Conclusion. This study demonstrated the association of low preoperative blood potassium concentrations with the risk of POAF. Electrolyte concentrations alone cannot fully explain the risk of arrhythmia. However, optimizing electrolyte balance and, in particular, maintaining potassium concentrations >4,5 mmol/L may prevent the atrial fibrillation in some patients.

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