Year: 2026
Type: dissertation
Study design: Observational Study
Abstract: BACKGROUND Based on historical studies of leadless pacemakers (LPs), high atrioventricular 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. OBJECTIVEThe purpose of this study was to investigate the predictors of A4 amplitude preoperatively to select patients who could benefit the most from AVS among patients with VDD LPs (Micra-AV, Medtronic). METHODSData from patients who received Micra-AV implantations from November 2021 to August 2023 at Tottori University Hospital were analyzed.Twelve-lead electrocardiography and transthoracic echocardiography were performed before the Micra-AV implantations.To assess the electrical indices associated with the A4 signal, electrocardiographic morphologic P-wave parameters were analyzed, including P-wave duration, P-wave amplitude, maximum deflection index (MDI), and P-wave dispersion.RESULTS A total of 50 patients who underwent Micra-AV implantations (median age 84 years; 64% male) were included and divided into 2 groups based on the median value of A4 amplitude, the high-A4 group (A4 amplitude >2.5 m/s 2 ; n 5 26), and low-A4 group (A4 amplitude 2.5 m/s 2 ; n 5 24).There was a significant difference between the high-A4 and low-A4 groups with regard to left ventricular ejection fraction (P 5 .01),P-wave dispersion (P 5 .01),and MDI (P <.001).Multivariate logistic analysis revealed that lower MDI was an independent predictor of high A4-amplitude (odds ratio 0.78; 95% confidence interval 0.67-0.92;P 5 0.003).CONCLUSION Preoperative electrocardiographic evaluations of P-wave morphology may be useful for predicting A4 amplitude.MDI was the only independent A4 amplitude predictor that seemed promising for selecting Micra-AV patients.
Author: 川谷, 俊輔
Institution: Tottori University
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7208488641