Catheter cryoablation of cardiac arrhythmias.

PURPOSE OF REVIEW The purpose of the review is to provide an update on the safety and efficacy of catheter cryoablation. RECENT FINDINGS Catheter cryoablation is a safe and clinically effective method for ablation of atrioventricular nodal reentrant supraventricular tachycardia. Although the acute procedural success rate of catheter cryoablation for this arrhythmia may be slightly lower than that reported for radiofrequency ablation, it has an excellent safety profile, with no reported instances of inadvertent atrioventricular block requiring implantation of a permanent pacemaker. Using this technology, one can perform reversible cryomapping, which helps to identify suitable ablation targets while identifying sites where cryoablation should be avoided. For patients with midseptal and parahissian accessory pathways, in whom the risk of producing inadvertent atrioventricular block is substantial, catheter cryoablation is a safe and effective alternative to radiofrequency ablation. Catheter cryoablation of common atrial flutter causes much less patient discomfort than radiofrequency ablation, with excellent acute and long-term efficacy. Catheter cryoablation also can be used to isolate the pulmonary veins during ablation of atrial fibrillation. As compared with radiofrequency ablation, the risk of acute thromboembolic complications and of pulmonary vein stenosis appears to be lower with cryoablation. SUMMARY For many cardiac arrhythmias, catheter cryoablation is a safe and effective alternative to radiofrequency ablation. The ability to identify suitable ablation targets by reversible cryomapping is a particularly useful feature of this technology. Although the acute procedural success rate of cryoablation may not equal that of radiofrequency ablation in all circumstances, as catheter technology evolves it is likely that the efficacy of cryoablation will improve and the list of arrhythmias that can be treated with this method will expand.