The P-Wave Time-Domain Significant Features to Evaluate Substrate Modification After Catheter Ablation of Paroxysmal Atrial Fibrillation

Abstract

The outcome of catheter ablation (CA) of atrial fibrillation (AF) is vastly analyzed by the entire P-wave duration (PWD). However, the first and second P-wave parts, corresponding to right (RA) and left atrial (LA) wavefront propagation, may be unequally modified. Five-minute lead II recordings before and after the first-ever CA of 40 parox-ysmal AF patients were analyzed and P-wave features were calculated: $PWD_{on-off}$ of the entire P-wave and each P-wave part $(RA:PWD_{on-peak},\ LA:PWD_{peak-off})$ and the time from P-wave onset or offset to the R-peak $(PWD_{on-R}$ and $PWD_{off-R}$, respectively). Heart-rate (HR) adjustment $(HRA)$ mitigated the HR fluctuations. Prelpost-CA comparison was performed with Mann-Whitney U-test and median values were calculated. Pearson's correlation was calculated between PWD and the remaining features. The effect of CA with $(\Delta$: −17.96%) or without HRA $(\Delta$: −9.84%) was significant at the entire $PWD_{on-off}$ and at the $PWD_{peak-off}(HRA:\Delta$: −27.77%, no HRA: $\Delta$: −22.03%). $PWD_{on-off}$ showed a stronger correlation with RA than $LA(\rho_{max}=0.805 \ vs \ \rho_{max}=0.541)$. P-wave features corresponding to RA are more strongly related to the entire P-wave. Nevertheless, only the P-wave part associated with LA is significantly affected by CA. That being so, studies are encouraged to incorporate part-time P-wave analysis.