Abstract

Given a paucity of data, the aim of this study was to define predictors of steam pops (SPs) during open-irrigated radiofrequency ablation (RFA).SPs during RFA can lead to dire consequences, including perforation and stroke.In an ex vivo bovine myocardium model, open-irrigated RFA was applied at 50 W for 60 s; intracardiac echocardiographic images for RFA with and without SPs was compared. Using an in vivo porcine model, open-irrigated RFA was applied at 50 W for 60 s, and RFA parameters of SPs were analyzed. A retrospective analysis was performed of recorded SPs during clinical ablation procedures over a 1-year period.For RFA SPs, there was 32% greater intracardiac echocardiographic tissue echogenicity than for RFA without SPs (p < 0.001). In addition, RFA SPs had more rapid increases of tissue echogenicity, particularly in the last 5 s before SPs. Compared with RFA without SPs, RFA SPs had larger impedance reductions (33.0 ± 16.0 O vs. 23.0 ± 10.8 O; p = 0.032). SPs were also associated with more rapid initial impedance reduction (1.40 O/s vs. 0.38 O/s for RFA without SPs; p = 0.001). Clinical SPs during ablation procedures had a significantly faster impedance reduction during the first 5 s of ablation compared with matched control ablations (15.7 ± 6.7 O vs. 8.1 ± 4.7 O; p < 0.0001).Certain echocardiographic and biophysical parameters during open-irrigated RFA are associated with increased SP risks. These include greater tissue echogenicity, larger total impedance reduction, rapid rate of initial impedance reduction, and rapid increase in tissue echogenicity.

View details for DOI 10.1016/j.jacep.2017.10.003

View details for PubMedID 30067489