The features of distinctive bipolar intracardiac electrograms for ventricular arrhythmias in the DGCV system origin.

Aims: To investigate the characteristics of bipolar intracardiac electrograms (bi-EGMs) in target sites of ventricular arrhythmias (VAs) originating from the distal great vein system (DGCVs).

Methods: 169 patients undergoing first-time ablation for VAs originated from DGCVs were enrolled in present study. Successful ablation was achieved in 146 patients. Bi-EGMs on successful sites were recorded and analyzed.

Results: In the 146 cases, the DGCVs was subdivided into DGCV (100 cases), AIV (28cases), and summit-CV (18 cases) subgroup based on anatomic location of final target site. An A and V wave were consistently recorded in Bi-EGM of target sites. A total of 59 cases showed A/V ≥ 1 while 87 patients were < 1. The incidence of A/V ≥ 1 recorded in target sites was higher in the DGCV subgroup (52%, 52/100) compared to the AIV (10.71%, 3/28) and summit-CV (22.22%, 4/18) subgroups (all p < 0.05). In A/V > 1 cases, pacing-induced ventricle capture, atrium capture or alternate atrium and ventricle capture, and no chamber capture were 83.05%(49/59), 6.78%(4/59),10.19%(6/59), respectively, and they were 90.80%(79/87), 1.15%(1/87), 8.05%(7/87) (p > 0.05) in 87 cases of A/V < 1. A presystolic multicomponent fractionated potential was frequently observed in target sites of DGCVs VAs(102/146, 69.86%), with the DGCV subgroup being more frequent than the AIV and summit-CV subgroups (74/100, 74% vs. 19/28, 67.86% vs. 9/18, 50%).

Conclusion: Catheter ablation of VAs arising from DGCV system is challenging. Different from traditional concept of atrioventricular annulus VAs, whose AV ratio of target sites should be less than 1, A/V ≥ 1 could be observed in VAs arising from DGCVs. In this region, target site identification should not be restrained by AV ratio. In addition, the presence of specific potentials in Bi-EGMs, can serve as an indicator for identifying target sites.

Clinical Trial Number: Not applicable.