Introduction:
Catheter ablation for atrial fibrillation (AF) and substrate-modification of the anterior left atrial (LA) wall could block conduction over the Bachmann bundle and change the P-wave. We aimed to examine the association of P-wave changes after pulmonary vein isolation (PVI) and anterior substrate ablation with atrial arrhythmia recurrence (AFr).
Methods:
We retrospectively analyzed 52 patients who underwent AF ablation at the Heart Center Leipzig between 2016 and 2021. All patients had sinus rhythm (SR) at the beginning of the index procedure and underwent anterior LA substrate-modification of low-voltage areas (LVA; <0.5mV in sinus rhythm). P-wave was evaluated in leads I, II, III, aVF, and V1 right before and after ablation. We measured manually on digitally enlarged ECGs the P-wave duration (ms) and amplitude (mV) of the initial positive (if monophasic) and/or later negative component of biphasic P-waves. We calculated the elliptic P-Wave area before and after ablation. We used SPSS.v25 and Cox regression analysis to identify independent AFr predictors.
Results:
Patients were of 74±9 years, mostly female (62%) with persistent AF (73%), CHADS-VA Score of 4 (3-5), LVA (90%) and at least one previous PVI (67%). The ablation changed P-wave components in lead I and the inferior leads. During follow-up of mean 3 (±2) years there were 25 patients with AFr (48%). Patients without AFr had similar clinical characteristics to those with AFr, but a significant increase of the P-wave area (³0 ) in inferior leads, especially lead II (1.221 vs. 0.035 , p=0.016). Multivariate analysis adjusting for previous ablation/substrate modification identified the increase in P-wave area in lead II as an independent AFr predictor (HR: 0.733, 95% CI 0.59-0.90, p=0.004).
Conclusion:
Substrate modification with anterior left atrial ablation changes the P-wave morphology. An increase in P-wave area in lead II is an independent predictor of success that could help inform patient management.
