High-resolution structural-functional substrate-trigger characterization: Future roadmap for catheter ablation of ventricular tachycardia

Abstract

IntroductionPatients with ventricular tachyarrhythmias (VT) are at high risk of sudden cardiac death. When appropriate, catheter ablation is modestly effective, with relatively high VT recurrence and complication rates. Personalized models that incorporate imaging and computational approaches have advanced VT management. However, 3D patient-specific functional electrical information is typically not considered. We hypothesize that incorporating non-invasive 3D electrical and structural characterization in a patient-specific model improves VT-substrate recognition and ablation targeting.Materials and methodsIn a 53-year-old male with ischemic cardiomyopathy and recurrent monomorphic VT, we built a structural-functional model based on high-resolution 3D late-gadolinium enhancement (LGE) cardiac magnetic resonance imaging (3D-LGE CMR), multi-detector computed tomography (CT), and electrocardiographic imaging (ECGI). Invasive data from high-density contact and pace mapping obtained during endocardial VT-substrate modification were also incorporated. The integrated 3D electro-anatomic model was analyzed off-line.ResultsMerging the invasive voltage maps and 3D-LGE CMR endocardial geometry led to a mean Euclidean node-to-node distance of 5 ± 2 mm. Inferolateral and apical areas of low bipolar voltage (<1.5 mV) were associated with high 3D-LGE CMR signal intensity (>0.4) and with higher transmurality of fibrosis. Areas of functional conduction delay or block (evoked delayed potentials, EDPs) were in close proximity to 3D-LGE CMR-derived heterogeneous tissue corridors. ECGI pinpointed the epicardial VT exit at ∼10 mm from the endocardial site of origin, both juxtaposed to the distal ends of two heterogeneous tissue corridors in the inferobasal left ventricle. Radiofrequency ablation at the entrances of these corridors, eliminating all EDPs, and at the VT site of origin rendered the patient non-inducible and arrhythmia-free until the present day (20 months follow-up). Off-line analysis in our model uncovered dynamic electrical instability of the LV inferolateral heterogeneous scar region which set the stage for an evolving VT circuit.Discussion and conclusionWe developed a personalized 3D model that integrates high-resolution structural and electrical information and allows the investigation of their dynamic interaction during arrhythmia formation. This model enhances our mechanistic understanding of scar-related VT and provides an advanced, non-invasive roadmap for catheter ablation.

The Fluoroless Future in Electrophysiology: A State-of-the-Art Review

“…Six skin patches are also applied on the patient that allow for the measurement of the level of impedance at the tip of the catheter, which provides useful information both during the mapping and ablation phases [31,32]. Improved anatomic resolution can be reached by integrating the electroanatomic maps with computer tomography scans or magnetic resonance imaging 3D reconstruction [33][34][35][36]. The CARTO-3 system is the last version of the system and allows the integration of magnetic fields with electrical fields such as those used by other EAM systems.…”

Arrhythmogenic vulnerability of reentrant pathways in post-infarct ventricular tachycardia assessed by advanced computational modelling

“…New imaging advances in diffusion tensor imaging sequences and non-invasive information from body surface mapping may help to individualize these parameters in the near future. 15 At the same time, prospective studies should also evaluate the required complexity of virtual heart models, as any further personalization will complicate the clinical implementation as well and may not necessarily improve procedure success.…”