Mapping the Maze: How 3D Imaging is Transforming VT Ablation in Congenital Heart Disease

Introduction: The Growing Challenge of Ventricular Tachycardia in Congenital Heart Disease

As surgical and medical management of congenital heart disease (CHD) has advanced, a growing population of adults with repaired or palliated CHD has emerged. However, this success brings a new set of clinical challenges, most notably the high prevalence of late-onset arrhythmias. Sustained monomorphic ventricular tachycardia (VT) is a significant cause of morbidity and sudden cardiac death in this population. Unlike VT in patients with ischemic cardiomyopathy, the substrate in CHD is uniquely complex, often characterized by heterogeneous scars from prior surgical incisions, patches, and the underlying congenital malformation itself.

Catheter ablation has become a cornerstone of VT management, yet success rates in CHD have historically lagged behind other etiologies. The primary obstacle is the three-dimensional complexity of the cardiac anatomy, which makes traditional electroanatomical mapping (EAM) exceptionally difficult. Identifying critical isthmuses—the narrow corridors of viable myocardium that support reentrant circuits—is often akin to finding a needle in a haystack. The CORECA study (Impact of Congenital Substrate 3D Imaging Reconstruction to Guide VT Catheter Ablation) sought to determine if preprocedural 3D imaging could provide a roadmap to simplify these procedures and improve outcomes.