New technologies for catheter ablation of atrial fibrillation

The past decade of ablation for atrial fibrillation (AF) has seen the adaptation of catheters designed for "focal" tachycardias or single pathways to perform wide encirclement of the pulmonary veins (PV). During the next decade, technologies designed specifically for PV isolation will emerge. Each system has its unique attributes. The cryoballoon system offers rapid PV isolation and the promise of enhanced safety, whereas the success rate is likely to be similar to catheter-based approaches. Although preclinical studies do suggest a very low likelihood of left atria-esophageal fistula using this technology, concerns of phrenic nerve damage and a small incidence of PV stenosis need to be addressed. It is likely that use of the larger 28-mm balloon will mitigate these concerns. The cryoballoon is also the first balloon technology to be approved by the US Food and Drug Administration for clinical use, and this may gain the technology an early foothold in the AF ablation market. The laser balloon ablation system is a more time-consuming and technically demanding procedure, and the risk of thrombus formation if ablation is performed in stagnant blood is a concern. However, early studies suggest a high rate of persistent PV isolation, which hopefully will translate into high single-procedure efficacy. The Ablation Frontiers system is the only system currently being developed for more persistent forms of AF. This system offers a rapid approach to PV isolation and left atrial defragmentation. The early results do not demonstrate a success rate better than that described for catheter ablation; however, the results are difficult to compare to standard catheter ablation in this recalcitrant patient group without a prospective randomized study.