Feasibility of Rapid Linear-Endocardial and Epicardial Ventricular Ablation Using an Irrigated Multipolar Radiofrequency Ablation Catheter

Background-A common strategy for ablation of scar-based ventricular tachycardia is delivering multiple lesions in a linear pattern. Methods and Results-We tested the efficacy of a novel linear irrigated multipolar ablation catheter capable of creating linear lesions with a single application. Healthy swine underwent endocardial and epicardial linear ablation using a novel linear irrigated ablation catheter; control animals underwent focal lesions in a linear pattern over 3.5 cm with an irrigated radiofrequency catheter. The linear catheter contained 7 irrigated electrodes spaced over 3.5 cm and could deliver <= 25 W to each electrode. Linear ablation required significantly less radiofrequency time than focal ablation (56 +/- 11 versus 497 +/- 110 seconds; P<0.0001). At gross pathology, linear (n=18) epicardial lines were longer than focal (n=8) epicardial lines (3.3 +/- 0.7 versus 2.1 +/- 0.9 cm; P<0.0005), with greater volume (3.8 +/- 2.9 versus 1.5 +/- 1.6 cm(3); P=0.002). There was no difference between linear (n=22) and focal (n=7) endocardial line length or volume. Gaps (length 2.8 +/- 0.9 mm) were present in 53% of focal lines and 0% of linear ablation lines. No perforations, steam pops, or thrombus were noted. Conclusions-Compared with sequential focal radiofrequency ablation in a linear pattern, an irrigated multipolar linear ablation catheter safely delivers contiguous endocardial or epicardial lesions without gaps in a single ablation. This catheter shows promise for decreasing ventricular tachycardia ablation procedure time and improving outcome.