Characterization of Contact Force During Endocardial and Epicardial Ventricular Mapping

Abstract

Background— The optimal contact force (CF) for ventricular mapping and ablation remains unvalidated. We assessed CF in different endocardial and epicardial regions during ventricular tachycardia substrate mapping using a CF-sensing catheter (Smartouch; Biosense-Webster) and compared the transseptal versus retroaortic approach. Methods and Results— In total, 8979 mapping points with CF, and force vector orientation (VO) were recorded in 21 patients, comprising 13 epicardial, 12 left ventricular (6 transseptal and 6 retroaortic approach), and 12 right ventricular endocardial maps. VO was defined as adequate when the vector was directed toward the myocardium. During epicardial mapping, 46% of the points showed an adequate VO and a median CF of 8 (4–13) g, however, with significant differences among the 8 regions. When VO was inadequate, median CF was higher at 16 (10–24) g ( P <0.0001). During left ventricular and right ventricular endocardial mapping, 94% of VO were adequate. Median CF of adequate VO was higher in the left ventricular and right ventricular endocardium than in the epicardium (15 [8–25] and 13 [7–22] g versus 8 [4–13] g, respectively; both P <0.001). Global median left ventricular CF with transseptal approach was not statistically different from retroaortic approach, but CF in the apicoinferior and apicoseptal regions was higher with transseptal approach ( P <0.001). Conclusions— Ventricular mapping demonstrates important regional variations in CF, but in general, CF is higher endocardially than epicardially where poor catheter orientation is associated with higher CF. A transseptal approach may lead to improved contact particularly in the apicoseptal and inferior regions.

The year in cardiology 2015: arrhythmias and device therapy.

“…Multiple important studies have been reported within the last 12 months documenting the importance and increased utilization of VT ablation. Despite several remarkable technical and technological improvements and innovations such as use of image integration, 26 novel ablation electrodes, 27,28 forcesensing technologies, 29 or ultra-high density mapping, 30 the relatively high recurrence rate of any VT after catheter ablation in patients with VT and structural heart disease remains a key challenge. As evident from recent multi-centre data, non-inducibility of any VT at the end of the ablation is probably the best endpoint for the procedure and should be targeted.…”

“…These and other issues are elegantly described in the 2015 updated version of the European Heart Rhythm Association practical guide, 21 following the great success of its first version published in 2013. 29 or ultra-high density mapping, 30 the relatively high recurrence rate of any VT after catheter ablation in patients with VT and structural heart disease remains a key challenge. As evident from recent multi-centre data, non-inducibility of any VT at the end of the ablation is probably the best endpoint for the procedure and should be targeted.…”

Real-Time Contact Force Measurement

“…Although the presence of epicardial fat has a considerable modifying effect on lesion formation, the catheter also has a more parallel orientation on the epicardial surface, so that the applied CF has a greater lateral than axial component, resulting in altered lesion geometry. 46,47 Such force vector information could be useful to prevent pulmonary lesions during epicardial RF ablation. 47 These insights have recently been reported to be helpful for successful CF-guided endocardial and epicardial ablation of ventricular tachycardia.…”

Contact Force During VT Ablation

“…Although the optimal CF for ventricular mapping and ablation has yet to be determined, in this issue of Circulation: Arrhythmia and Electrophysiology, Jesel et al 6 provide important insights into regional variations in CF and catheter orientation relating to epicardial and endocardial mapping. Briefly, the authors evaluated CF variability using a cooled-tip mapping/ablation catheter (Thermocool SmartTouch, Biosense Webster, Inc, Diamond Bar, CA) during endocardial and epicardial mapping in a cohort of patients with and without structural heart disease undergoing catheter ablation of VT, by 2 experienced operators blinded to the collected CF data.…”

“…Further research is needed to enhance our understanding and interpretation of the available data in the hopes of continuing to improve the outcomes from VT ablation. As such, the article by Jesel et al 6 represents an excellent starting point.…”