Mapping and ablation of RVOT-type arrhythmias: comparison between the conventional and reversed U curve methods.

PURPOSE: We assessed conventional and reversed U curve methods for mapping and ablation of RVOT-type VAs.

METHODS: Single-center data were reviewed from consecutive cases of symptomatic VAs of RVOT-type origin that were mapped and ablated successfully using conventional method in RVOT (pulmonary artery might be included) from January 2014 to December 2015 (cohort 1, n = 75) or conventional method in RVOT and reversed U curve in PSC (for first ablation attempt) from January 2016 to March 2017 (cohort 2, n = 60).

RESULTS: At least 90% of RVOT-VAs could be eliminated using conventional method in RVOT or reversed U curve in PSC. For RVOT-VAs, if the earliest activation site was in midposterior free wall, midposterior septal side of RVOT, or anterior free wall/septal side of RVOT with conventional method, it was likely eliminated in right, left, and anterior PSC with reversed U curve method, respectively. Nearly the same earliest potential in almost the same region could be recorded by both methods. Compared with conventional method, the reversed U curve method showed better catheter stability and contact force during mapping and ablation, and showed distinctive features in presystolic potential recording, unipolar mapping, and ablation response.

CONCLUSIONS: Most of RVOT-VAs could be eliminated using conventional method in RVOT or reversed U curve in PSC. However, the reversed U curve method has superiority in catheter stability and contact force, especially for VAs form free wall of RVOT.