Detection of premature ventricular contraction/ventricular tachycardia origin comparing the non-invasive and invasive mapping systems

During the initial step, consecutive ectopic beats were analysed to reproducibly define the focal SOO. Foci were displayed on separate non-invasive isopotential maps, the latter of which were based on anatomical data derived from CT or MRI. In a second step, all non-invasively determined foci were marked on the same cardiac model and the distance between each was measured using the ‘ruler’ tool of the NEEES software.

Next, the NEEES data were compared with the results of the invasive procedure. The left ventricle (LV) was divided into 16 segments: right coronary cusp (RCC), left coronary cusp (LCC), aorto-mitral continuity (AMC), anterior mitral valve (MV), septal MV, posterior MV, lateral MV, basal anterior LV, basal septal LV, basal posterior LV, basal lateral LV, mid-anterior LV, mid-septal LV, mid-posterior LV, mid-lateral LV, and apical LV. The right ventricle (RV) was divided into 18 segments: anterior RV outflow tract (RVOT), lateral RVOT, posterior RVOT, septal RVOT, anterior tricuspid valve (TV), lateral TV, posterior TV, septal TV, parahisian (PH) RV, basal anterior RV, basal lateral RV, basal posterior RV, basal septal RV, mid-anterior RV, mid-lateral RV, mid-posterior RV, mid-septal RV, and apical RV (Figure 2).

Diagram of segmentation of the ventricles. Detailed are the numbers of PVC/VT foci within the respective ventricular segment. Cases incorrectly identified by non-invasive mapping are marked within the diagram.

Preceding the invasive electrophysiology study, the NEEES data were analysed and the PVC/VT was categorized as RV or LV in origin and then subcategorized according to the RV/LV segment. During invasive mapping, the SOO was localized using the CARTO 3 system and compared with the SOO predicted by the NEEES. The SOO was considered identical if localized within the same heart segment. Final confirmation of the SOO was made by successful catheter ablation.