Evaluation of safety and the success rate of cryoballoon ablation of the pulmonary vein ostia in patients with atrial fibrillation--a preliminary report.

BACKGROUND: Cryoballon isolation of the pulmonary veins has recently emerged as a promissing technique for ablation of atrial fibrillation (AF).

AIM: To present our initial experience in cryoballon isolatin of the pulmonary veins in patients with AF.

METHODS: Eight patients (5 males; age 59+/-2 years) with AF: 2 with persistent and 6 with paroxysmal (5 of them after unsuccessful RF ablation) with >or=6 month follow-up after the procedure were included. One patient after myocardial infarction was treated with primary angioplasty with stent implantation. Another one had biatrial pacemaker. The procedure was performed with cryobaloon with 28 mm diameter (Arctic Front--Cryocath). After transseptal puncture mapping of the pulmonary vein ostia was performed with Lasso catheter (Johnson and Johnson). At each pulmonary vein ostium with pulmonary vein potentials 2 cryoapplications of 300 s duration was performed. Correct balloon placement before cryoapplication was checked using contrast injection into the pulmonary veins. During cryoapplication in the right pulmonary vein ostia permanent pacing of the phrenic nerve 30 beats per minute was performed to prevent its paralysis. After cryoapplications in all veins remapping with Lasso catheters was performed. In the absence of pulmonary vein potentials the procedure was finished, otherwise next cryoapplications were performed. During follow-up ECG was performed if any palpitations occurred, and 24-hour Holter monitoring was performed 1, 2 ,4, 6, 8, 10 and 12 months after the procedure. A 2-month blanking period after the procedure was used. The lack of symptomatic AF and the absence of AF>30 s on Holter ECG monitoring were defined as successful procedure. An improvement was defined as reduction of frequency/duration of AF paroxysm and reduction of the EHRA index>or=1.

RESULTS: During 8 procedures isolation of 31 pulmonary vein was performed. Procedure duration was 3.5+/-0.85 h, fluoroscopy time--33.55+/-15.44 min, and total cryoapplication time--38.33+/-4.1 min. There were no complications. After the follow-up of 8.5+/-0.99 months 6 (75%) patients were free from arrhythmia, including the patient after myocardial infarction and one patient with permanent AF prior ablation. In another patient an improvement was observed (EHRA score II/III to I) whereas in one patient with permanent AF the procedure was unsuccessful.

CONCLUSION: Cryoballoon ablation of pulmonary vein ostia is effective and safe, and can be an alternative to RF ablation. Easier procedure technique make possible shortening of the learning curve and increase the number of treated patients.