Impact of P-wave morphology on recurrent arrhythmia characteristics and low-voltage risk score in paroxysmal atrial fibrillation patients underwent catheter ablation

Abstract Background The P-wave morphology’s impact on clinical outcomes post-catheter ablation (CA) and recurrent arrhythmia characteristics or electrophysiological findings in paroxysmal atrial fibrillation (PAF) patients remains unclear. Purpose The aim of this study was to elucidate the impact of combination of Pd and Pvm (Pd/Pvm) on the clinical outcomes after CA and recurrent characteristic or electrophysiological findings in repeated ablation. Methods PAF patients who underwent CA in the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry were enrolled. P-wave duration and P-wave vector magnitude (the square root of the sum of the squared P-wave amplitude in leads II, V6 and one-half of the P-wave amplitude in V2) were measured. We divided the patients into two groups; patients with high and low Pd/Pvm based on the cut-off value calculated by statistical methods. We evaluated (1) late recurrence of atrial fibrillation (AF) / atrial tachycardia (AT) (LRAF) (2) clinical risk score for low-voltage area (DR-FLASH score) and (3) recurrent characteristics and electrophysiological findings in repeated ablation between the two groups. Results This study included 1005 PAF patients. The median follow-up duration was 722 [288, 1119] days. LRAF occurred in 251 patients (25.0%). A cut-off value of Pd/Pvm=699.1ms/mV gave AUC=0.87, sensitivity=72.9%, specificity=85.3%. High Pd/Pvm had a greater risk of LRAF than low Pd/Pvm (p<0.001). The ratio of the patients with DR-FLASH score>3 was significantly higher in those with high Pd/Pvm than low. The ratio of AT recurrence was significantly higher in the patients with high Pd/Pvm than in those with low Pd/Pvm (32.4% vs 18.8%, p=0.034). The ratio of AT occurring during repeated ablation and reproducible frequently occurring atrial premature contractions or AF triggers in left atrium (LA) were significantly higher in the patients with high Pd/Pvm than low Pd/Pvm. Conclusion Combination of P-wave morphology, Pd/Pvm, was significantly associated with LRAF. Pd/Pvm was significantly correlated with clinical risk score for predicting LA low-voltage area and incidence of AT and LA-origin AF triggers.