Friendly Fire During RF: Be Firm But Gentle!

Abstract

activation mapping of arrhythmias, atrial fibrillation/atrial arrhythmias, cardiac mapping -3-dimensional systems, catheter ablation -atrial fibrillation Editorial CommentThe contact between the target tissue and the ablation electrode is the major determinant of lesion size and transmurality of ablation lesions.1 Contact force guided ablation offers us the promise of predictable transmural lesions and hence it is currently one of the hottest topics in electrophysiology practice.The adoption of force-sensing technology has been very rapid and there is an honest optimism of about it being a giant step forward for ablation outcomes. The last such major advance was the introduction of irrigated catheters. Although most of the clinical development of this technology has been for atrial fibrillation ablation, the exciting scope of contact force sensing is allowing much wider field of application and acceptance in ablation of other substrates. 2-5However, whether force sensing technology is capable of producing a paradigm shift in atrial fibrillation ablation will need to be assessed critically in the future, although the trends suggest that it will. 6,7 While the ablationist is happy that RF energy applications are now going to be more effective, we need to be cognizant that with the precise firepower of these ablation catheters comes more caution. There are data to suggest that using 5-10 g of force is optimum for creating chamber geometry comparable to CT but at least 10 g of force, preferably 20 g, is required during energy applications to achieve durable RF lesions. 8,9 As an optimum force time interval (400-500 gramseconds) is being considered as a good surrogate for lesion quality, one can imagine the effect of having a reasonably high force within limits (<40-50 g) to reduce energy application time at a particular target.1 However, force being a continuous variable, incremental application of the same in a soft tissue chamber like the heart or vessels will initially result in progressive stretching of the chamber wall with potential wall disruption, even without energy application. The catheterinduced chamber wall tenting has the potential of bringing the tip of the ablation electrode in closer proximity to adjacent anatomical structures and their collateral but unfortunate involvement during radiofrequency energy application.