Ablation catheter orientation: In vitro effects on lesion size and in vivo analysis during PVI for atrial fibrillation

Abstract

Background Catheter‐delivered radiofrequency (RF) lesion formation is a complex phenomenon, and few studies have explored the effect of catheter orientation on lesion size and catheter orientation behavior during pulmonary vein isolation (PVI) procedures. We evaluated the influence of catheter orientation on lesion dimensions in an in vitro experimental setting and investigated the catheter orientation behavior during PVI. Methods and results 72 lesions were created in vitro on a porcine heart using a contact force catheter in a parallel, oblique, and perpendicular tip to tissue orientation. The superficial lesion length (SLL) increased shifting the catheter from perpendicular to parallel orientation. The intratissue absolute maximal lesion length (AML) was greater with an oblique catheter orientation. The lesion depth (LD) and the superficial lesion width (SLW) resulted similar with any orientation. Data from 21 PVI procedures in patients with paroxysmal atrial fibrillation using the “wide antral circumferential RF ablation” (WACA) technique were retrospectively analyzed. The mean contact angle among 1130 RF lesions was 28 ± 20°. A prevalent parallel orientation was noted in the anterior WACA segments, whereas it resulted more perpendicular in the posterior segments. Significant differences in catheter orientation between the three operators were found only in few WACA segments. Conclusions In an in vitro setting, catheter orientation affects SLL and AML, but not LD and SLW. During PVI procedures, catheter orientation resulted mostly parallel to the endocardium. Catheter orientation varied among different WACA segments, but only small differences were found between three operators when considering similar WACA segments.

Impact of catheter contact angle on lesion formation and durability of pulmonary vein isolation

“…Recent in vitro study demonstrated by V. Calzolari et al [11] is consistent with our study. RF lesions created on a porcine heart with different contact angles were evaluated, and they measured both superficial lesion size and crosssectional lesion size.…”

“…An in vitro study was conducted under limited setting of CF, ablation time, and power. To avoid steam pop phenomenon, lower CF and lower power were selected compared with other in vitro studies [11][12][13][14]. CF variability was not evaluated, and it is not clear whether the lesion size difference of in vitro study is clinically significant.…”

Fluid–Structure Interaction and Non-Fourier Effects in Coupled Electro-Thermo-Mechanical Models for Cardiac Ablation

“…Apart from the RF electrode insertion depth, we have also numerically investigated the effects of RF electrode orientation on the treatment outcomes of cardiac ablative procedures. Motivated by [55], three RF electrode to tissue orientations have been considered, viz., perpendicular (90 • ), oblique (45 • ) and parallel (0 • ), as depicted in Figure 6a. The temperature distributions obtained for these three orientations have been presented in Figure 6b-d considering ε = 0.3 and u in = 3 cm/s.…”

Catheter contact angle influences local impedance drop during radiofrequency catheter ablation: Insight from a porcine experimental study with 2 different LI-sensing catheters

“…Several studies have demonstrated that the catheter contact angle is an important factor in lesion creation. [16][17] [18] In an in vitro study, Calzolar et al reported [17] that the superficial lesion widths were increased by shifting the catheter angle from the perpendicular to the parallel orientation, and the intratissue maximal lesion widths were greater with an oblique catheter orientation than with a perpendicular position using a 3.5-mm tip, open-irrigated, CF-sensing catheter (TactiCath SE; Abbott, St. Paul, MN, USA). Conversely, they also reported that the lesion depths were not different with different catheter orientations.…”