Catheter Ablation -> Ventricular Arrhythmias -> Ablation Techniques D-PO05 - Poster Session V (ID 39) Poster

D-PO05-182 - On Developing Novel Safety Indices For Bipolar Radiofrequency Ablation In Human Myopathic Model (ID 1297)


Background: Bipolar EGMs amplitude reduction and impedance drop across the tips of two ablation electrodes from two catheters have not been tested for power titration. We used ex-vivo beating animal hearts to test and then validated in human heart Langendorff set up.
Objective: To establish safety of bipolar RF ablations power titration with inter-catheter bipolar EGM amplitude and inter- catheter impedance.
Methods: Ablations using two 4 mm non-contact force catheters were performed in 6 human explanted hearts and 8 Pig Hearts. Parameters: 20-50W/60s, 30ml/min irrigation.
Results: Ninety-three ablations were performed in 14 hearts.Low power ablations (20 & 30W)-For tissue thickness of 10-15mm, 15-20mm and in >20mm- 23 of 27 ablations (85%), 6 of 17 ablations (35%) and 2 of 10(20%) were transmural respectively. Combining 20W and HNS, 12 of 18(67%) were transmural, and steam pop 1/18(5%).
High power ablations (40 & 50W)- For tissue thickness of 10-15mm, 15-20mm and in >20mm, 4 of 5 ablations (80%), 5 of 11 ablations (45%) and 3 of 12(25%) were transmural respectively.
Monitoring- For transmural and non-transmural lesions- 70 ± 10% and 40 ± 20% decrement in bipolar inter-catheter EGM amplitude occurred respectively. In ablations with and without steam pop, impedance decrement was 31 ± 6% and 22 ± 7% respectively.
Conclusion: Bipolar ablation at 20-30W was sufficient to achieve transmurality in majority of ablations in <15 mm ventricular wall thickness. Use of HNS with low power had maximal incremental benefit and low risk of steam pop. Monitoring inter-catheter impedance and bipolar EGM voltage could refine safety and efficacy.