Electrophysiological characteristics and radiofrequency ablation of sustained monomorphic ventricular tachycardia in adult patients with isolated ventricular noncompaction

Purpose: This study examined electrophysiological characteristics and outcomes of patients with sustained ventricular tachycardia (VT) in the setting of isolated ventricular noncompaction (IVNC). Background: In patients with IVNC, VT has been associated with sudden cardiac death. However, the electrophysiological characteristics and optimal management of these VTs are only incompletely understood. Methods: This retrospective cohort study assessed arrhythmia characteristics and outcomes in IVNC patients with sustained monomorphic VTs. Data were obtained from five academic centers covering the time period from January 1, 2006, to December 31, 2016, with a median follow-up of 40 months. Results: Eighteen consecutive IVNC patients with sustained VTs (12 males [66%], mean age of 44.4 ± 16.9 years) were enrolled. Seven (39%) patients underwent VT ablation (five males, mean age of 43.3 ± 15.5 years) and nine (50%) patients received ICD therapy. Six of 18 patients (33%) died during a median follow-up of 40 months. Of these, three had ICDs, two had undergone VT ablation, and one had received only antiarrhythmic drugs. Among the seven patients with prior VT ablation, five VTs in the RV (three RVOT and one tricuspid annulus) and two LV VTs (one anterolateral papillary muscle and one inferolateral wall) were localized by 3-D mapping and successfully ablated. In six of seven ablation cases (85.7%), the VTs were distant from the noncompaction zone. VTs appeared to be focal in 57% (4/7) and macro-reentry in 43% (3/7) of patients based on 3-D mapping and entrainment studies. The success rate of VT ablation was 85.7% with one VT recurrence and two deaths during the mean follow-up of 54 (28–115) months. Conclusions: IVNC Patients with sustained VTs appear to have a poor prognosis despite receiving ICD or apparently successful VT ablation therapy. Further, most VTs appear to arise remote from the noncompaction zone. Whether these VTs were “idiopathic” or related to IVNC was uncertain.