Role of Preoperative P-Wave Characteristics in Forecasting Postoperative Atrial Fibrillation After Cardiac Surgery

All articles of this category (opens in new window) Background: Postoperative atrial fibrillation (POAF) remains the most common arrhythmic complication following cardiac surgery, with significant clinical and economic consequences. While numerous clinical and perioperative risk factors have been described, electrocardiographic (ECG) P-wave parameters (PWPs) have emerged as promising markers of atrial electrical vulnerability. This study aimed to evaluate whether these PWPs can predict the development of POAF. Methods: We retrospectively analyzed seven P-wave parameters—P-wave duration, interatrial block, P-axis, P-voltage in Lead I, P-area in Lead II, P-terminal force in V1, and P-wave dispersion—in 602 patients with documented preoperative sinus rhythm who underwent various cardiac surgical procedures at our center between January 2021 and December 2023. Baseline characteristics, 12-lead ECGs, and postoperative outcomes were assessed using univariate and multivariable logistic regression. Receiver operating characteristic (ROC) analyses were performed to evaluate discriminative performance and define optimal cut-off values. Results: In our cohort, 44 patients (7.3%) developed POAF. Patients who developed POAF were older (68 ± 8 vs. 64 ± 10 years; p = 0.004) and more frequently in higher NYHA classes ( p < 0.001), but did not differ significantly in sex, body mass index (BMI), or body surface area (BSA). Preoperatively, both P-wave duration (131 ± 14.9 ms vs. 122 ± 16.0 ms; p < 0.001) and P-wave dispersion (106.6 ± 13.6 ms vs. 96.7 ± 18.7 ms; p < 0.001) were significantly increased in patients who developed POAF. In multivariable models, only P-wave dispersion remained independently predictive of POAF (OR 1.03 per ms, 95% CI: 1.00–1.06; p = 0.044). An optimal P-wave dispersion cut-off of 97.5 ms was identified (sensitivity 0.80; specificity 0.50). Patients above this threshold had a significantly higher incidence of postoperative AF/Flutter (7.3%) compared with the low-dispersion group. ROC analysis yielded an area under the curve (AUC) of 0.708, indicating moderate discriminatory power. Conclusion: P-wave dispersion, and to a lesser extent, prolonged P-wave duration, reflect atrial conduction heterogeneity and remodeling, and may serve as clinically relevant predictors of POAF. However, their predictive performance is modest, and standardized measurement protocols are lacking. Linking P-wave indices to atrial substrate vulnerability can improve risk prediction. With AI-assisted ECG analysis, these indices may further guide targeted ablation strategies and left atrial appendage occlusion, ultimately enhancing patient care. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany