Left Pulmonary Veins Isolation: The Cornerstone in Noninvasive Evaluation of Substrate Modification After Catheter Ablation of Paroxysmal Atrial Fibrillation

While pulmonary vein isolation (PVI) is the cornerstone of the paroxysmal atrial fibrillation (pAF) treatment, whether left (LPVI) and right PVI (RPVI) provoke equal atrial substrate modifications (ASMs), vastly assessed by P-waves, remains unexplored.Five-minute recordings from 40 pAF patients undergoing first-time PVI were extracted before PVI (B), after LPVI (L) and RPVI (R) at 1 kHz sampling rate.Signal-averaged P-wave features of duration, amplitude and area were calculated.Heartrate fluctuations (HRF) were mitigated for duration and area (HR Dur,area ).Results were compared between each transition (B-L: LPVI, L-R: RPVI) and between variations in values due to transitions with non-parametric tests.Duration ( B-L : -13.3%, p = 0.001, L-R : +2.40%, p = 0.558) and amplitude B-L : -17.29%, p = 0.055, L-R : +5.65%, p = 0.319) got decreased after LPVI and slightly increased after RPVI.HRF mitigation mostly preserved these trends but lost statistical power (HR Dur : B-L : -10.54%, p = 0.141, L-R : -5.52%, p = 0.740).LPVI showed a significantly higher effect on duration than RPVI (p < 0.0001).Variations observed in P-wave features after PVI stem principally from LPVI, which contributes significantly to the ASM.Studies focusing on ASM observation should implement and prioritize the analysis of LPVI recordings.