The procedural characteristics of radiofrequency ablation points in patients undergoing atrial fibrillation ablation: comparison between standard vs very high-power short-duration

Abstract

Abstract Introduction Atrial fibrillation ablation has a central role in the treatment of atrial fibrillation. Radiofrequency (RF) ablation is one of the possible energy sources used for the procedure. Recently, the development of new catheters has made it possible to modify the amount of power delivered by moving from a standard ablation to a very high-power short-duration (VHPSD). The objective of the study is to compare the delivery features of the RF points between standard RF vs VHPSD. Methods All the patients underwent RF ablation of paroxysmal atrial fibrillation. The procedure was performed using an electroanatomical mapping system under conscious sedation. All patient received a heparin bolus for ACT>300. The anatomy of the left atrium was reconstructed with a high-density catheter. Radiofrequency (RF) was applied following a wide antral circumferential approach (WACA) obtaining the isolation of the veins. The use of the ablation catheter was at the discretion of the operator and the choice was between a standard open-irrigated catheter with force sensor (Smartouch SF) and an irrigated, temperature-controlled contact-force sensing capable of delivering VHPSD (QDOT MICRO). For every patient, data from each individual RF delivery point were collected and analysed. Results A total of 72 consecutive patients were collected (26 QDOT group vs 46 standard group). Average total number of ablation point for obtaining complete pulmonary vein isolation with WACA was lower in the QDOT group (QDOT group 37,8±11 vs 42,1±18 standard group). As expected, the average duration (QDOT group 3.9±0.1s vs 12.7±2.4s standard group) and the average power delivered was significantly different between the two group (QDOT group 89,8±0.8W vs 33.0±1.4W standard group). Average basal impedence was similar (QDOT group 133.2±11,6 ohm vs 122.4±11,4ohm standard group) while impedence drop was significantly different (QDOT group 12.2±2.4 vs 9.9±2.4s standard group). Conclusion VHPSD ablation allows isolation of the pulmonary veins to be achieved with fewer ablation points and more quickly. It is also associated with a greater impedence drop during delivery. More studies are needed to see if this also corresponds to a lower number of recurrences after ablation.