Evaluation of myocarditis in a pediatric population using cardiovascular magnetic resonance and endomyocardial biopsy

Objectives: To evaluate myocarditis in a pediatric population using cardiovascular magnetic resonance (CMR) and endomyocardial biopsy. Methods: Twenty suspected for myocarditis patients aged 8-16 years and 20 controls were evaluated. CMR was performed using STIR T2-weighted (T2W), early T1-weighted (EGE) and late gadolinium-enhanced images (LGE). Immunohistologic and polymerase chain reaction (PCR) analysis of myocardial specimens were employed in 8/16, who fulfilled the criteria for myocarditis according to clinical and CMR findings. Results: Typical clinical, ECG and echocardiographic presentation were identified in 10/16. Troponine I was positive only in 3/16 patients. T2 and EGE in myocarditis were increased compared to controls (2.35 +/- 0.5 vs. 1.57 +/- 0.13, p<0.001 and 8.5 +/- 3 vs. 3.59 +/- 0.08, p<0.001, respectively). LGE was found only in 10/16 patients. Endomyocardial biopsy, performed in 8/16 patients with positive CMR, showed positive immunohistology in 2/8 and presence of viral genomes in 6/8 (Herpes, Parvo B19 and Epstein-Barr). Left ventricular ejection fraction (LVEF) was significantly decreased compared to controls (49.6 +/- 14.8 vs. 64 +/- 0.2, p<0.001). After 6 months, CMR showed normalization of T2, EGE and decreased/or absent LGE. LVEF was normal in all, except two, who remained with low LVEF but in a stable clinical condition. Conclusions: In a small Greek pediatric population with myocarditis, CMR proved useful for the detection of myocarditis, especially in those with negative troponine and mild clinical presentation. (C) 2011 Elsevier Ireland Ltd. All rights reserved.