Catheter Ablation -> Ventricular Arrhythmias -> Mapping & Imaging D-PO06 - Poster Session VI (ID 26) Poster

D-PO06-106 - Performance And Limitations Of Cardiac Magnetic Resonance Imaging To Detect The Critical Ventricular Tachycardia Substrate In Non-ischemic Dilated Cardiomyopathy (ID 667)


Background: Cardiac magnetic resonance (CMR) imaging is an increasingly utilized tool to detect areas of fibrosis in patients with non-ischemic dilated cardiomyopathy (NIDCM), with the purpose of guiding ablation procedures or detecting potentially arrhythmogenic areas for risk stratification. However, the performance of CMR to characterize the critical arrhythmogenic substrate (CAS) of NIDCM has not been systematically evaluated.
Objective: We studied the performance of CMR to detect the CAS of NIDCM.
Methods: A total of 35 patients (86% male, 53±13 years, left ventricular ejection fraction 39±11%) with NICM underwent detailed characterization of the CAS demonstrated to participate to VT with activation, entrainment and/or pace mapping during sinus rhythm as well as high density endo/epicardial EAM mapping. A pre-procedural CMR was performed in all patients. Segment per segment correlation analysis of late gadolinium enhancement (LGE) substrate localization with the CAS determined with invasive mapping was performed.
Results: LGE was present in 29 of 35 patients (83%) with endocardial/midmyocardial distribution in 13, subepicardial in 11 and both in 5 patients. Segmental analysis comparing CAS with regions of LGE showed a concordance in 79% of endocardial segments and 87% of epicardial ones. CAS were present in 24% of endocardial segments showing evidence of LGE vs. 10% of those without (p<0.01) and in 34% of epicardial segments with LGE vs. 3% without (p<0.01). Overall, pre-procedural CMR missed a total of 69% endocardial CAS and 37% of epicardial CAS.
Conclusion: In patients with NIDCM, the overall agreement of LGE on CMR and the critical VT substrate proven with contact mapping is poor and heterogeneous, with up to 69% of critical VT sites in regions with no visible LGE. Further work is required to improve the accuracy of CMR.