Prevalence and predictive factors of left atrial tachycardia occurring after second-generation cryoballoon ablation of atrial fibrillation
Résumé
Introduction: Assess the prevalence and predictors of left atrial tachycardia (LAT) after cryoballoon ablation of pulmonary veins. Methods and results: Patients who underwent catheter ablation of pulmonary veins with a second-generation cryoballoon for symptomatic paroxysmal (151 of 270, 56%) or persistent (119 of 270, 44%) atrial fibrillation were entered in a single-center prospective registry. Patients who experienced postcryoballoon LAT (pcryo-LAT) were selected on the basis of 12-lead ECG characteristics. Left atrial origin was confirmed during conventional EP study and electroanatomical activation mapping, and patients were treated by RF catheter ablation. Pcryo-LAT was observed in 15 (5,6%) of 270 patients and was attributed to a reentrant mechanism in 11 patients (73%).The other four cases of pcryo-LAT were due to focal atrial tachycardia associated with reconnection of one pulmonary vein. In comparison with patients who remained in sinus rhythm, LA area (HR = 1.09; CI 1.01,1.2; P = 0.02), LVEF (HR = 0.94; CI 0.90,0.97; P< 0.001), and LVEF<50% (HR = 8,5; CI 3.1, 23,6; P< 0.001) were predictors of pcryo-LAT. After multivariate Cox analysis, only left ventricular ejection fraction< 50% remained predictive of pcryo-LAT, (HR = 7,8, CI 2.3 26.7, P = 0.002). With a mean survival of 23 months, 73% of patients who experienced pcryo-LAT were in sinus rhythm versus 78% of patients without pcryo-LAT (log rank P = 0.85), Conclusion: The prevalence of pcryo-LAT in patients with atrial fibrillation is low. Left ventricular ejection fraction< 50% is associated with an increased risk of pcryo-LAT. When treated by RF catheter ablation, the presence of pcryo-LAT is not a predictive factor of subsequent recurrence of atrial fi bri llation during fol low-up.