Predictors of atrial tachyarrhythmias inducibility after pulmonary vein isolation in patients with paroxysmal atrial fibrillation

Aim. To identify predictors of atrial tachyarrhythmias inducibility after pulmonary vein isolation in patients with paroxysmal atrial fibrillation (AF). Methods. The study included 82 patients (63,65±9,21 years, 45 men (54,9%)) with paroxysmal AF referred for primary radiofrequency ablation. All patients underwent voltage mapping of the left atrium, with areas exhibiting bipolar signal amplitudes less than 0.5 mV identified as low-voltage areas (LVA). After pulmonary vein isolation, arrhythmia induction was performed by pacing with a cycle length of 180 milliseconds sequentially from the left atrial appendage, anterior wall, roof, posterior wall, and mitral isthmus area. When sustained tachycardia was induced, electrophysiological mapping of the left atrium was performed to verify the tachycardia mechanism. Results. Tachyarrhythmias were not induced in 25 patients (30,48%), while 57 patients experienced induced tachyarrhythmias of varying durations (69,52%). The arrhythmia mechanisms in patients with induced sustained tachycardias were macro re-entry in 12 cases (38,7%), atrial fibrillation in 12 cases (38,7%), and a combination of macro re-entry and atrial fibrillation in 7 cases (22,6%). We found a statistically significant correlation between the induction of any type of arrhythmia and body mass index (p=0.014) and left atrial volume (p=0.024). A correlation was also found between AF induction and left atrial volume (p=0.016) and the percentage of LVA (p=0.014). The threshold value of the percentage of LVA indicating the probability of AF induction was 2.2%. No correlation was found between macro re-entry induction and any of the investigated factors. Conclusions. Independent predictors of sustained arrhythmia induction were left atrial volume and body mass index. Atrial fibrillation induction was associated with left atrial volume and LVA percentage with a threshold of ≥2.2%. No significant associations with the investigated parameters were found for macro re-entry.