At the ESC 2025 Congress, cardiologists from Santa Maria University Hospital, Lisbon, presented prospective data comparing conventional electrocardiography (ECG) and electrocardiographic imaging (ECGi) for predicting ablation targets in ventricular tachycardia (VT) among patients with structural heart disease.

Accurate localization of the VT exit site is essential for successful ablation, but ECG alone often falls short. In this study, 17 patients (median age 71 years, 88% male, 53% ischemic cardiomyopathy) underwent both ECG and non-invasive ECGi before left ventricular VT ablation. Blinded ECG interpretations were performed by three general cardiologists and three electrophysiologists using a validated 17-segment prediction model, while ECGi utilized a 252-electrode 3D mapping system (CardioInsight™).

The results revealed striking differences: physicians using ECG correctly predicted VT exit sites in only 48% of cases, with electrophysiologists outperforming general cardiologists. By contrast, ECGi achieved 88% accuracy, significantly surpassing both groups (p=0.003). Moreover, ECGi pinpointed the exact VT exit site without margin of error in 82% of patients, compared with less than 6% for clinicians.

The study positions ECGi as a promising adjunct to invasive mapping, with the potential to streamline ablation procedures, minimize procedure time, and improve patient safety. Future multicenter studies with larger cohorts will help determine whether ECGi should be integrated into routine pre-ablation workflows, especially for complex structural heart disease cases.