Cryoballoon ablation of atrial fibrillation.

Pulmonary vein isolation using a cryoballoon has evolved into a relatively simple alternative for point-by-point radiofrequency ablation because this technology theoretically allows for PV isolation with a single application. Recent clinical studies indicate a high efficacy rate of the procedure; however, the incidence of the most common complication-phrenic nerve palsy (PNP)-has been reported in up to 11.2% of cases. Based on the present data, PNP is mainly associated with the use of the smaller 23 mm balloon. Very recently, it became evident that cryoballoon ablation may be associated with PV stenosis. Thus, the use of cryoballoon technology needs to be combined with a strategy aiming for maximal patient safety. The "single big (28 mm) cryoballoon technique" is a straightforward single-device strategy to deploy cryothermal lesions proximal to the PV ostium at the antrum level, thereby reducing the risk of collateral damage. Using this technique the endpoint of complete PV isolation was achieved in 97% of patients in our laboratory. PNP was observed in 4.4% of patients and resolved within 12 months in the majority of cases. In the future, development of an even bigger (32 mm) cryoballoon may further increase procedural safety by reducing the risk of PNP or PV stenosis.