Remotely Navigated Ablations in Ventricle Myocardium Result in Acute Lesion Size Comparable to Force-Sensing Manual Navigation.

Abstract

October 2019 1 Ventricular arrhythmias are one of the most life-threatening conditions. Radiofrequency ablation (RFA) is one of the most important treatment options for ventricular tachycardia. The therapy is constantly advancing with modern technology implementation.1 RFA invasive treatment is commonly performed via catheter with the support of 3-dimensional electroanatomic mapping systems,2 with either manual navigation (MAN) or robotic remote magnetic-navigated (RMN) catheters3 (Figure [A]). A comparative and contact force-stratified biophysical evidence of the RMN ablation features is still missing and might impair further spreading of the technique and its benefits. The data that support the findings of this study are available from the corresponding author upon reasonable request. The protocol used in this study was approved by the Ethical Commission of Veterinary and Pharmaceutical University in Brno. The study was performed on ten 6-month-old female large white swine (weight 50–60 kg). The animals were prepared and monitored as previously reported.4 The animals were divided into 5 groups of 2 pigs, according to target force (MAN-5G, -10G, -15G, and -20G to compare with RMN). Carto 3 (Biosense Webster Inc) was used to support navigation and ablation. Each animal underwent 8 endocardial RFA applications in selected areas of the left ventricle (Figure [B]) Orientation of the catheter tip to the wall of the heart was as perpendicular as possible. The same generator settings were used in all study groups (40 W with limited power if the temperature exceeded 50°C, maximum duration of 60 seconds, irrigation rate of 20 mL/min). Whole hearts were fixed in 10% PFA and scanned in transversal view by 9.4T MRI (Soucek et al, under review). Selected lesions were then cut on the transversal plane and prepared for histopathologic examination via hematoxylin/ eosin staining. If not otherwise stated, continuous data are presented as raw means±SDs. For groups comparisons, the significance levels were calculated using the F test with Kenward-Roger adjustment. An ablation composite index (ACI) was implemented in this study, to integrate all the procedural parameters and findings, defined as Equation 1: