Radionuclide imaging for assessment of myocarditis and postmyocarditic state in infant and children. Thallium-201 myocardial imaging and technetium-99m-HSA gated equilibrium ventriculography.

T1-201 myocardial imaging and Tc-99m-HSA gated equilibrium ventriculography were performed in 1 infant and 11 children between 2 months old and 12 years old with myocarditis. The time of first evaluation was between 1 week and 13 months after the onset. Their clinical manifestations were congestive heart failure in 2 patients, pericardial effusion in 2 patients, syncope in 1 patient, convulsions in 1 patient and palpitations in 7 patients. Significant elevation of virus antibody titer was demonstrated in 6 patients. A perfusion defect was observed with T1-201 imaging in 9 of 12 patients with myocarditis. A right ventricular image was observed in 5 patients. A reduced LVEF was present in 4 patients and a reduced RVEF was found in 2 patients. Cardiac catheterization was performed in 8 patients and an endomyocardial biopsy was done in 7. The myocardial specimens revealed postmyocarditic pathological changes upon microscopic evaluation. No coronary artery obstructive or stenotic lesions were observed in these patients. T1-201 myocardial imaging is a useful non-invasive technique for evaluating the cardiac performance and myocardial damage in acute myocarditis and the postmyocarditic state. We conclude that T1-201 uptake of myocardium is dependent upon both regional coronary perfusion and the activity of myocardial cells in patients with myocarditis and in the postmyocarditic state.