Characteristics of redo procedures of patients after pulmonary vein isolation using cryoballoon ablation technique

Objective To summarize the characteristics of redo procedures in patients after cryoballoon ablation for atrial fibrillation and to provide guidance for future cryoballoon technique. Methods From December 2013 to December 2015, nine consecutive patients with prior cryoballoon ablation for atrial fibrillation and recurrent atrial tachyarrhythmia were retrospectively enrolled.All patients underwent radiofrequency irrigation catheter ablation guided by 3-dimentional mapping system for pulmonary vein re-isolation and other inducible tachycardia.The ipsilateral pulmonary vein antrum was divided into six equally distributed segments for the analysis of the location of conduction gaps. Results All the 10 patients were male with an average age of(48.4±10.9)years.Three patients had persistent atrial fibrillation and 7 patients presented paroxysmal atrial fibrillation.During the prior cryoballoon ablation, all 41 pulmonary veins, including 1 common left pulmonary vein(CLPV), 9 left superior pulmonary veins(LSPV), 9 left inferior pulmonary veins(LIPV), 10 right superior pulmonary veins(RSPV), 10 right inferior pulmonary veins(RIPV)and 2 right middle pulmonary veins(RMPV), were successfully isolated using single 28 mm cryoballoon with an average of(12.3±1.9)cryoablation applications per one patient.These patients presented recurrent atrial tachyarrhythmia during follow-up and underwent redo procedures in(4.8±2.3)months after the cryoballoon ablation.Twenty-one pulmonary veins(51.2%), including 1 CLPV, 3 LSPV, 7 LIPV, 4 RSPV and 6 RIPV, exhibited reconduction during redo procedures.Among all the 10 patients, one patient exhibited no pulmonary vein reconduction while other patients exhibited varying numbers of pulmonary vein reconduction.The reconduction sites(23 sites in total)were more frequent in inferior pulmonary veins.All the reconducted pulmonary veins were successfully re-isolated.And radiofrequency ablation was applied in additional superior vena cava isolation in one patient, typical atrial flutter in one patient, peri-mitral atrial flutter in one patient and atrio ventricular nodal reentrant tachycardia in one patient.During a median follow-up of 5 months, one patient presented recurrent paroxysmal atrial fibrillation which could be well controlled by anti-arrhythmia drugs.The other patients remained in sinus rhythm during follow-up. Conclusion Patients underwent prior cryoballoon ablation for pulmonary vein isolation exhibited relatively lower rate of reconduction, which presented in favored sites(i.e.inferior pulmonary veins). Re-isolation of pulmonary veins, along with additional ablation for other triggers and tachycardia, is effective and safe for the treatment of recurrent atrial tachyarrhythmia.