Abstract 18548: Rapid Linear Ventricular Ablation Using a Novel Irrigated Multipolar Radiofrequency Ablation Catheter
Introduction: A common strategy for ablation of scar-based VT is delivering multiple lesions in a linear pattern. We tested the efficacy of a novel linear irrigated multipolar ablation catheter (nMARQ, Biosense-Webster) capable of creating linear lesions with a single application.
Methods: Healthy swine (n = 7) underwent endocardial (endo) and epicardial (epi) linear (LIN) ablation; control animals (n = 5) underwent focal (FOC) lesions in a linear pattern with an irrigated RF catheter (Thermocool). The LIN catheter contained 7 irrigated electrodes spaced over 3.5 cm and could deliver up to 25 W energy to each electrode (Fig 1A). Control FOC lesions were delivered contiguously over a 3.5 cm length from 20-35 W to achieve a >10 ohm impedence drop for each lesion (Fig 1B). In 2 additional swine, ablation was performed 1 month after an infarct was created using LAD balloon occlusion. Endo and epi LIN ablation was performed over the scar border zone. After sacrifice, hearts were sectioned for gross pathology, imaged, and lesion dimensions digitally measured.
Results: Compared to FOC, LIN ablation required significantly less RF time (56 ± 11 vs 497 ± 110 sec; p < 0.0001). At gross pathology, LIN (n = 18) epi lines were longer than FOC (n = 8) epi lines (3.3 ± 0.7 vs 2.1 ± 0.9 cm; p = 0.001), with greater total volume (3.8 ± 2.9 vs 1.5 ± 1.6 cm3; p = 0.04). There was no difference between LIN (n = 22) and FOC (n = 7) endo line length or volume. Gaps (length 2.8 ± 0.9 mm) were present in 8/15 (53%) FOC lines and 0/40 LIN lines. In infarct animals, LIN lesion volume was no different from LIN ablation in healthy animals (1.9 ± 1.5 vs 3.2 ± 2.1 cm3; p = 0.60). No perforation, steam pop or thrombus was noted.
Conclusions: Compared with sequential focal RF ablation in a linear pattern, an irrigated multipolar linear ablation catheter safely delivers contiguous endo or epi lesions without gaps in a single ablation. This catheter shows promise for dramatically decreasing VT ablation procedure time and improving outcome.
Author Disclosures: B. Nazer: None. T.E. Walters: None. S. Duggirala: None. E.P. Gerstenfeld: Research Grant; Significant; Biosense-Webster. Honoraria; Modest; Biosense-Webster.
- © 2016 by American Heart Association, Inc.