Predictor of A4-amplitude using preprocedural electrocardiography in patients with leadless pacemakers

Abstract Background Based on the historical studies of leadless pacemakers (LP), high atrio-ventricular synchrony (AVS) with mechanical sensing-based VDD pacing is largely influenced by A4-amplitude. A limited study investigated the predictors of A4-amplitude using clinical and echocardiographic parameters. Objective This study aimed to investigate the predictors of A4-amplitude preoperatively to select patients who could benefit the most from AVS among patients with VDD LPs. Methods Data from patients who received VDD LP implantations from November 2021 to August 2023 at our institution were analyzed. Twelve-lead electrocardiography and transthoracic echocardiography were performed before VDD LP implantations. To assess the electrical indices associated with the A4-signal, the electrocardiographic morphological P-wave parameters were analyzed including the P-wave duration, P-wave amplitude, maximum deflection index (MDI), and P-wave dispersion. Results A total of 50 patients who underwent VDD LP implantations (median age, 84 years; 64% male) were included and divided into two groups based on the median value of A4-amplitude, the high-A4 group (A4-amplitude >2.5m/s2, n=26) and low-A4 group (A4-amplitude ≤2.5m/s2, n=24). There was a significant difference between the high-A4 and low-A4 groups in the LVEF (P=0.01), P-wave dispersion (P=0.01), and MDI (P<0.001). A multivariate logistic analysis revealed that a lower MDI was an independent predictor of a high A4-amplitude (odds ratio: 0.78, 95% confidence interval: 0.67 to 0.92; P=0.003). Conclusion Preoperative electrocardiographic evaluations of the P-wave morphology may be useful for predicting A4-amplitude. The MDI was the only independent A4-amplitude predictor that seemed promising for selecting VDD LP patients.abstract figure