Ratio of P-wave Duration to P wave Amplitude and Left Atrial Remodeling: Insights from Electrophysiological Findings and Myocardial Injury after Cryoballoon Ablation.

The impact of the P-wave morphology on clinical outcomes post-catheter ablation (CA) and recurrent arrhythmia characteristics or electrophysiological findings in paroxysmal atrial fibrillation (PAF) patients remains unclear. PAF patients who underwent cryoballoon ablation were enrolled. In twelve-lead electrocardiography recorded within one-month before CA, the P-wave duration (Pd) and P-wave vector magnitude (Pvm) (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 and divided into two groups; patients with high and low Pd/Pvm based on a statistically calculated cut-off value. We evaluated the incidence of late recurrence of AF (LRAF), myocardial injury (high-sensitive troponin I [hs-TnI]) and the electrophysiological findings in repeat ablation sessions. This study included 269 PAF patients. The median follow-up duration was 697 days. The cut-off value of the Pd/Pvm for predicting LRAF was 740.7ms/mV (AUC=0.81, sensitivity=58.2% and specificity=89.6%). Multivariable Cox proportional hazards analysis showed high Pd/Pvm (>740.7ms/mV) was significantly associated with LRAF (p<0.001). The hs-TnI level was significantly lower and ratio of DR-FLASH score>3 significantly higher in those with high than low Pd/Pvm (p=0.044, p=0.002, respectively). In the repeat ablation sessions, the Pd/Pvm in patients with atrial tachycardia (AT) induced or spontaneously occurring during the repeat CA sessions was significantly higher than in those without (p=0.009). There was a significant difference between the Pd/Pvm and low-voltage area (LVA) (p<0.001). In conclusion, the Pd/Pvm is significantly associated with LRAF after cryoballoon ablation in PAF patients and predicts left atrial LVAs and AT inducibility.