Endomyocardial biopsy findings in pediatric patients with post myocarditic state.

Endomyocardial biopsy was performed on eight children 5 to 12 years old, who were in post myocarditic state. They were evaluated within 2 to 25 months (mean lyr and 1 m) after the onset of the symptoms. Two of the patients developed heart failure and six patients developed other cardiac manifestations such as syncope, palpitation or ECG abnormalities at onset. Definite elevation of viral antibody titer was observed in four patients. Radionuclide angiography was also performed in all eight patients. An abnormal perfusion area was observed in six patients as a focal hypoperfusion area by T1-201 myocardial imaging. Ejection fraction was examined by Tc-99m-HSA gated equilibrium ventriculography. LVEF was reduced in 3 patients and RVEF was reduced in 2 patients. Judging from the histopathological findings, these patients were divided into three categories: chronic or smoldering myocarditis (3 patients); healing or healed myocarditis (4 patients); and post myocarditic hypertrophy (1 patient). Measurement of left ventricular function was obtained by cardiac catheterization and left ventriculography (LVG), which revealed some abnormal findings such as increased left ventricular mass index, increased left ventricular end diastolic volume index (LVEDVI) and reduced left ventricular ejection fraction (LVEF). Therefore, endomyocardial biopsy findings of pediatric patients in a post myocarditic state reveal certain histopathological abnormalities even in the long-term follow-up period in the absence of cardiac dysfunction.