Abstract
Background
Pulmonary vein isolation (PVI) has become the mainstay of catheter ablation of atrial fibrillation (AF). There are two commonly used methods to isolate the pulmonary veins, either point-by-point delivery of circumferential lesion sets around ipsilateral pulmonary veins using radiofrequency energy, or the application of the cryoballoon to the pulmonary vein antrum with occlusion of the vein ostium. The cryoballoon has proven to be a reliable alternative to radiofrequency ablation in acute and long-term freedom from AF. We describe our results using both modalities.
Aim and Objectives
to compare the safety and efficacy of cryoballoon (CB) ablation and radiofrequency (RF) ablation in treatment of paroxysmal atrial fibrillation.
Patients and Methods
Forty-four consecutive patients having paroxysmal AF underwent PVI using the second generation cryoballoon were compared to a retrospective cohort of 69 patients who had radiofrequency induced PVI, either by conventional RF catheter (n = 32), or a contact-force sensing-catheter (n = 37). The study took place at Ain Shams university hospitals and Royal Brompton & Harefield NHS trust. Patient data, procedural data and follow up data- at 3, 6 and 12 months- were collected and analysed. Recurrence was defined as documented AF or atrial arrhythmias with duration exceeding 30 seconds, either by 12 lead ECG or an ambulatory monitoring device.
Results
A total of 113 patients were studied. The mean age was 53.84 ± 15.01 for the CB group and 55.78 ± 14.84 for the RF group and females representing 40.9% vs 34.8% respectively. The mean procedural times in minutes were significantly less in the CB group (94.37 ± 39.32 vs 184.57 ± 88.19, p < 0.0001), while the median fluoroscopy times were similar [30 (11.04 - 40) vs 37.25 (14.2 - 70), p = 0.172]. Procedural complications were comparable between the two groups (p = 0.06) with 1 patient (2.3%) having long term phrenic nerve paresis. At 1 year follow up, after an initial 90-day blanking period, recurrence rate of CB was similar to RF (27.3% vs 30.4% respectively, p = 0.719), the Kaplan Meier estimates of AF- free survival for a period of 1 year were comparable between both groups (log rank test, p = 0.606).
Conclusion
Cryoballoon is a feasible method for pulmonary vein isolation with similar success rates to radiofrequency ablation. Cryoballoon ablation is safe with shorter duration of the procedure.
Dissociated pulmonary vein rhythm may predict the acute pulmonary vein reconnection post-isolation in patients with paroxysmal atrial fibrillation
