Introduction: A new generation ablation system with an irrigated ablation catheter in conjunction with an advanced electro-anatomic mapping and navigation system allows the evaluation of the Electrical Coupling Index (ECI), an indication of tip-to-tissue contact. Aim of our study was to evaluate if this index could also give an indication about ablation lesion efficacy.
Methods: In patients undergoing typical right atrial flutter ablation, we compared the values of the ECI before, during (at the plateau) and after isthmus ablation. Permanent tissue damage or ablation lesion efficacy was defined as the reduction in the local potential > 90% or as potential split in 2 separate signals. In absence of these endpoints, lesions were deemed ineffective.
Results: 15 consecutive patients (11 males, age 69.3±11.4 years) with history of typical atrial flutter underwent an ablation with Contact™ Therapy™ Cool Path™ Cardiac Ablation System in conjunction with EnSite™ Velocity Contact™ technology between Sep 2012 and Aug 2013. Target site for ablation was the isthmus between the inferior vena cava and the tricuspid valve. All the procedures were successful, without complications. The number of radiofrequency (RF) applications was 10.8±6.7 (range 6-28) and RF time was 330.3±177.5s. ECI values are reported in the table:RF effective applications needed less time and the ECI post-ablation was inferior compared to ineffective RF applications. The absolute and percentage ECI variations (pre-post ablation) were significantly greater when applications were effective (p < 0.001). From our data, it is possible to determine a 13% cut-off value in the ECI variation that could be considered as the target for an effective ablation
Conclusions: The Electrical Coupling Index can be used as a marker of ablation lesion efficacy in the the ablation of typical right atrial flutter.