Introduction: VT was associated with sudden cardiac death (SCD) in isolated ventricular noncompaction (IVNC). The electrophysiological characteristics of these VTs were unknown
Methods: Seven patients with IVNC undergoing VT ablation were included from five academic centers between Jan 1, 2006 and December 31, 2016. Twelve patients with VT ablation were identified from Pubmed search.
Results: VTs of 19 patients were mapped to RV in 10 (52.6%) and LV in 9 (47.4%). RV VTs were localized to RVOT (4, 40%), tricuspid annulus (4, 40%) and septum/epicardium (2, 20%). LV VTs were localized to mitral annulus (1, 11%), papillary muscle (2, 33%) and myocardial origin (6, 67%). VTs were localized to endocardial (68.8%) and epicardial (31.2%). 58.9% of all VTs were from outflow tract, annular or papillary muscle, away from the noncompaction zone. The mechanisms of VTs were focal in 68.8% and macro-reentry in 31.1%. Five patients (31%) received ICD implant with no VT therapy after ablation during the follow-up of 2 weeks to 63 months. Overall success rate from VT ablation was 78.9%.
Conclusions: VTs in patients with IVNC were evenly distributed in both RV and LV. More than half of these VTs were focal, endocardial and away from the noncompaction zone. Whether these VTs were “idiopathic” or related to IVNC were uncertain.