Log in to MyACC
VT Substrates in Children and Young Adults With Repaired TOF
Quick Takes
- Substrate for ventricular tachycardia in the form of a slow conducting anatomic isthmus (SCAI) was present in 29% of patients with tetralogy of Fallot (TOF) <30 years of age undergoing electrophysiology study.
- Risk factors for presence of an SCAI included right ventricle-to-pulmonary artery conduit/early pulmonary valve replacement, ventriculotomy, and complex TOF.
Study Questions:
What substrates exist for ventricular tachycardia (VT) in patients with repaired tetralogy of Fallot (TOF) <30 years of age?
Methods:
A retrospective review was performed at a single center. Routine electrophysiology studies were performed at the study institution for all patients ≤8 years of age undergoing pulmonary valve replacement (PVR). Data of consecutive patients with TOF aged <30 years of age who underwent electroanatomical mapping and programmed electrical stimulation between 2005 and 2022 were analyzed.
Results:
A total of 55 patients were included (median age, 15.8 years). Repairs were performed via ventriculotomy and 12 patients had complex variants of TOF. Twelve patients had right ventricle-to-pulmonary artery conduits placed at the time of initial repair or had early PVR (PVR within 1 year of initial repair). The vast majority of studies (40) were performed as routine screening studies prior to PVR, while five were performed for documented spontaneous VT and 10 performed for risk stratification. Slow conducting anatomical isthmus (SCAI) between the pulmonary valve and the ventricular septal defect (VSD) patch (SCAI 3) was seen in 16 (29%) patients. Monomorphic VT was inducible in eight and related to SCAI 3 in seven patients. Right ventricle-to-pulmonary artery conduit/early PVR, ventriculotomy, and complex TOF were associated with SCAI 3 in univariable analysis.
Conclusions:
The authors conclude that in young patients with repaired TOF, SCAI 3 is the dominant substrate for VT. Complex TOF, ventriculotomy, and timing of re-operation my contribute to the development of SCAI at a young age.
Perspective:
Ventricular arrhythmias are an important cause of morbidity and mortality in older adults with repaired TOF. The most common substrate is an SCAI between the pulmonary valve and VSD patch (SCAI 3). This study demonstrates that substrate for the development of ventricular arrhythmias is relatively common in young patients with TOF. The clinical implications of this, as well as the role for screening electrophysiology studies and proactive ablation approaches, require further study.
Clinical Topics: Arrhythmias and Clinical EP, Congenital Heart Disease and Pediatric Cardiology, SCD/Ventricular Arrhythmias, Congenital Heart Disease, CHD and Pediatrics and Arrhythmias
Keywords: Heart Defects, Congenital, Tachycardia, Ventricular, Tetralogy of Fallot
< Back to Listings
