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

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.