Abstract
Background The origin distribution of
right-ventricular-outflow-tract (RVOT) ventricular arrhythmias (VAs)
remains unclear. There is limited data on the ablation effectiveness of
the reversed U-curve method compared with the antegrade method.
Objectives To investigate the origin distribution of RVOT-type
VAs and compare the ablation effectiveness of the two methods.
Method Consecutive patients who had idiopathic RVOT-type VAs
were prospectively enrolled. After activation mapping, patients were
randomly assigned to supravalvular strategy using the reversed U-curve
or subvalvular strategy using the antegrade method. The primary outcome
was initial ablation (IA) success, defining as the successful ablation
within the first three attempts.
Results 61 patients were enrolled from November 2018 to June
2020. Activation mapping revealed 34/61 (55.7%) of the earliest
ventricular activating (EVA) sites were above the pulmonary valves
(PVs). The IA success rate was 25/33(75.8%) in the patients assigned to
supravalvular strategy as compared with 16/28(57.1%) in those assigned
to subvalvular strategy (P=0.172). Logistic regression revealed a
substantial and qualitative interaction between the EVA sites and IA
strategies (Pinteraction<0.001). For
multiple-comparison, either strategy had a remarkably higher IA success
rate in treating its ipsilateral EVA sites than contralateral ones
(P<0.0083).
Conclusion Of the idiopathic RVOT-type VA origins, half were
located above the PV. The two strategies did not differ in the primary
outcomes. However, they complement locating the EVA sites and facilitate
ipsilateral ablation, which produces a significantly higher IA success
rate. (Chinese Clinical Trial Registry number, ChiCTR2000029331)
Keywords: pulmonary valve, pulmonary sinus cusp, premature
ventricular contraction, radiofrequency, activation mapping
Abbreviations: EVA=earliest ventricular activating,
PA=pulmonary artery, PSC=pulmonary sinus cusp, PV=pulmonary valve,
PVC=premature ventricular contraction, PVVJ=pulmonary valve-ventricle
junction, RVOT=right ventricular outflow tract, VA=ventricular
arrhythmia, VT=ventricular tachycardia, RF=radiofrequency.
Funding: This work was supported by the Clinical Research
Center Project of Department of Science and Technology of Guizhou
Province [NO.(2017)5405]; the Guizhou Provincial High-level
Innovative Talents Project (GZSYQCC[2015]006); the Guizhou
Provincial Science and Technology Foundation (No.[2019]1197); the
Guizhou Provincial Science and Technology Social Development Project
(No.[2018]2794).