Lesion Formation by Ventricular Septal Ablation With Irrigated Electrodes: Comparison of Bipolar and Sequential Unipolar Ablation

• Published in: Circulation Journal 2011, Vol.75(3), pp.565-570
• Main Authors: Nagashima, Koichi, Watanabe, Ichiro, Okumura, Yasuo, Ohkubo, Kimie, Kofune, Masayoshi, Ohya, Toshiyuki, Kasamaki, Yuji, Hirayama, Atsushi
• Format: Article
• Language: English
• Subjects: Animals; Bipolar radiofrequency ablation; Catheter Ablation - instrumentation; Catheter Ablation - methods; Cooled-tip ablation; Electrodes; Interventricular septum; Models, Animal; Swine; Tachycardia, Ventricular - surgery; Ventricular Septum - pathology; Ventricular Septum - surgery
• ISSN: 1346-9843; 1347-4820
• DOI: 10.1253/circj.CJ-10-0870

Background: Ablation of ventricular tachycardia originating from the interventricular septum (IVS) is often limited by the presence of re-entrant pathways deep in the IVS. We compared the efficacy of bipolar ablation vs. sequential unipolar ablation in creating a transmural lesion across the porcine IVS. Methods and Results: Seventeen excised swine hearts were superfused by pulsatile saline flow. Bipolar ablation (at 30W, 50W or 70W for 120s) was performed between 2 saline-irrigated (20ml/min) 4-mm tip electrodes, 1 on the left and 1 on the right side of the IVS. Sequential unipolar ablation (at 30W, 50W or 70W for 120s) was performed on the left and right sides of the IVS with an irrigated-tip catheter. Bipolar ablation produced a narrower, deeper lesion than did unipolar ablation. A transmural lesion was created by sequential unipolar ablation in 7.7%, 8.3% and 0% of tissue preparations and by bipolar ablation in 50.0%, 46.7% and 71.4% of tissue preparations at 30W, 50W and 70W. Conclusions: Bipolar ablation of the IVS was highly effective for creating a transmural IVS lesion. (Circ J 2011; 75: 565-570)