Pranav Bhagirath

196 Chapter 10 Table 2. Comparison of PVC focus identified with IPM and ablation site on EAM. Case PVC focus IPM Ablation site 1 NCC-LCC junction LCC 2 RVOT-Septal RVOT-Septal 3 RVOT-Anterior proximal RVOT-Anterior proximal 4 RVOT-Anterior RVOT-Anterior 5 RVOT-Septal proximal RVOT-Septal proximal 6 RVOT-Antero-septal RVOT-Septal 7 RVOT-Postero-septal RVOT-Septal 8 NCC NCC NCC indicates non-coronary cusp; LCC, left coronary cusp; RCC, right coronary cusp; LVOT, left ventricular outflow tract; RVOT, right ventricular outflow tract. In all 8 cases, IPM located the ectopic focus in the correct cardiac compartment ( table 2 ). IPM identified all RVOT foci in close proximity to the ablation lesion (8.4±3 mm, n=6) defined on the EAM ( figure 2 and movie 2 ). A similar difference was found for the LVOT foci (7.9±1.5 mm, n=2). IPM located one of the LVOT foci (Case 2) at the right-coronary cusp. However, the ablation for this patient was successfully performed in the distal LVOT ( figure 3 ). The other LVOT focus was closely approximated to the actual site of ablation. Comparison between homogeneous and inhomogeneous volume conductor models The comparisonof PVC focus between the inhomogeneousVCMand EAMdemonstrated a localization accuracy of 8.3±2.7 mm (observer 1) and 8.2±2.8 mm (observer 2) with a high inter-observer agreement (ICC=0.812, 95% CI [0.318 to 0.959], p=0.004 ). A similar comparison between the homogeneous VCM and EAM demonstrated an accuracy of 10.3±3.1 mm (observer 1) and 9.8±2.9 mm (observer 2) and also showed a high inter- observer agreement (ICC=0.862, 95% CI [0.399 to 0.975], p=0.003 ). The focus localization accuracy showed significant differences between the homogeneous and inhomogeneous VCM’s. The homogeneous VCM had a significantly higher localization error compared to the inhomogeneous VCM for both observers ( table 3 ) ( p=0.043 ). In addition, the homogeneous VCM failed to identify the focus in one RVOT case ( figure 4 , case 6) where the inhomogeneous model correctly identified the site of ablation.