Midwall Late Gadolinium Enhancement and Native T1 Elevation in Chronic Myocarditis-Related Dilated Cardiomyopathy: An Evidence-Based Case Report.

摘要

BACKGROUND: Cardiovascular magnetic resonance (CMR) is the reference standard for non-invasive myocardial tissue characterization, with proven value in diagnosing and prognosticating myocarditis and non-ischemic dilated cardiomyopathy (DCM). This study aimed to present a case of chronic myocarditis/DCM phenotype and integrate it with evidence from high-quality studies on CMR diagnostic and prognostic utility. METHODS: An evidence-based case report (EBCR) framework was applied. Literature was systematically searched across PubMed, Cochrane Library, and ScienceDirect for studies evaluating CMR in myocarditis or DCM using the 2018 Lake Louise Criteria or equivalent multiparametric protocols. RESULTS: A 45-year-old female presented with mild exertional dyspnea. CMR revealed midwall late gadolinium enhancement (LGE) in the basal-to-mid interventricular septum, elevated native T1 values, and no T2 elevation. These findings fulfilled the T1-based criterion for chronic myocardial injury but not the T2-based edema criterion, indicating prior inflammation and residual fibrosis. Across the included studies, midwall LGE correlated with histopathology-confirmed myocarditis, predicted all-cause mortality and sudden cardiac death, and signaled risk of progressive ventricular dysfunction. Native T1 mapping improved sensitivity for detecting diffuse fibrosis even in the absence of widespread LGE. The patient's imaging profile aligns with chronic myocarditis, carrying a heightened arrhythmic and heart failure risk. Evidence supports intensified surveillance and consideration for device therapy in such profiles. CONCLUSION: CMR, through combined LGE and mapping techniques, offers essential diagnostic clarity and prognostic stratification in chronic myocarditis/DCM, enabling precise and individualized clinical management.