Abstract

BACKGROUND: Cardiac MRI aids identification of critical substrate in scar-dependent VT. Anatomical assessment (AA) of MRI images detects channels which may sustain VT and are viable targets for ablation. Heart digital twins (DT) combine anatomical data with functional assessment to identify the VT isthmus. OBJECTIVE: To assess the additional benefit of combining functional data with anatomy using a DT compared to purely anatomical assessment in identifying critical substrate in ventricular tachycardia (VT). METHODS: 18 patients with scar-dependent VT planned for catheter ablation underwent contrast-enhanced cardiac MRI. AA to derive conducting channels was performed. Simultaneously, heart DT models combining personalised heart geometry and functional properties were generated and tested for VT inducibility and optimum ablation lesion sites predicted. Patients underwent invasive VT ablation. Detection of scar and critical substrate was compared between AA and DT. RESULTS: Scar identification was similar between AA and DT. Total area predicted for ablation was similar between AA and DT (9.94cm2 [± 9.46cm2] vs 9.84cm2 [± 3.23cm2], p = 0.96). Sensitivity for detection of abnormal electrograms was greater with DT compared to AA (51.4% [± 17.6%] versus 25.3% [± 25.4%], p = 0.002). Sensitivity of detection of deceleration zones, mid-diastolic potentials (MDP) and sites of VT termination with ablation was higher with DT than AA, with DT correctly identifying 13/16 (81.3%) of MDP compared to 8/16 by AA (50.0%). CONCLUSIONS: Addition of functional data improves detection of critical substrate above purely anatomical assessment in scar-dependent VT. Digital twins are a potentially useful aid in VT ablation.