AbstractObjectivesTo evaluate any association between non‐sustained ventricular tachycardia (NSVT) detected by intra‐cardiac device and clinical outcomes in repaired adult congenital heart disease (ACHD) without tetralogy of Fallot (TOF).BackgroundNSVT portends a higher risk of serious ventricular tachyarrhythmia in TOF. However its clinical significance when incidentally detected by implantable cardiac device is not well elucidated in non‐TOF ACHD cohort.MethodsWe performed a single center, retrospective, longitudinal follow‐up study in repaired ACHD (≥18 years) patients without TOF who hosted a pacemaker or automatic implantable cardiac defibrillator (AICD). The cohort was divided based on presence/absence of device detected NSVT. The primary end‐point was a composite of sustained ventricular tachycardia (VT), ventricular fibrillation (VF), or sudden cardiac death (SCD).ResultsOne hundred fifty eight patients (male 56.3%, median [IQR] age of 35 [28–43] years at last follow‐up] with longitudinal post‐implant follow‐up duration of 8 (5–12) years were included. NSVT was detected in 52 (33%) patients. The primary composite end‐point was more frequent in NSVT group [11.5% vs. 2.8%; p = .04]. Patients with NSVT were (i) older at the time of initial implant (age 25 vs. 18 years, p = .011) and more frequently demonstrated (ii) systemic ventricular dysfunction (44% vs. 26%; p = .015), as well as (iii) history of ventriculotomy (38% vs. 21%; p = .017).ConclusionsIn our repaired ACHD cohort, we noted a significant association between device‐detected‐NSVT and the primary composite end‐point of sustained VT/VF or SCD. Systemic ventricular dysfunction and history of ventriculotomy were more frequent in the NSVT group and likely constituted the clinical milieu.