Abstract 4139879: Impact of Catheter Contact Angle on the Relationship between Contact Force and Local Impedance Change with the Novel Diamond-embedded Temperature-controlled Ablation Catheter in a Porcine Experimental Model

Background: The DiamondTemp TM (DT) catheter enables precise temperature-controlled ablation. However, the DT catheter lacks contact force measurement capabilities. This study investigated the impact of catheter contact angle on the relationship between contact force and local impedance change in a porcine experimental model. Hypothesis: We hypothesized that a correlation between contact force and local impedance would differ in different contact angles of the DT catheter. Aims: To evaluate the impact of different contact angles (30°, 45°, 90°) of the DT catheter on the relationship between the contact force and local impedance change. Methods: We used freshly sacrificed porcine hearts and set them in the circulated water pool. The contact force (5, 10, and 30 grams) and catheter contact angles (30°, 45°, and 90°) were changed in each set (n = 13 each). Local impedance was measured, and the correlation with contact force was assessed using Spearman's rank correlation coefficient. Results: Strong correlations were found between local impedance rise and contact force at catheter contact angles of 90° (Spearman’s rank correlation coefficient: 0.70, p <0.001) and 45° (0.60, p <0.001). However, there was no correlation between catheter contact force and local impedance rise at 30° (0.31, p = 0.057). Conclusion: Local impedance rise of the DT catheter was correlated with contact force at the catheter contact angle of 90° and 45°; however, it became insignificant at 30°, suggesting that local impedance could not be utilized to speculate contact force in the shallower catheter contact angles.