Perfusion scintigraphy of the myocardium was carried out with the help of the Millennium MG gamma camera (USA) in synchronization with the ECG in 141 patients aged of from 5 to 15 years. Patients were divided into four groups: 30 chronic myocarditis (CM) patients, 30 hypertrophic cardiomyopathy (HCMP) patients, 30 dilated cardiomyopathy (DCMP) cases and 21noncompact cardiomyopathy (NCMP) patients. The left ventricular (LV) ejection fraction was established to be preserved in CM and HCMC patients (in cases without signs of obstruction), a significant reduction in the ejection fraction was found in NKMP and DCMP patients. The thickness of the myocardium of the LV significantly increased only in HCM patients. The expansion of the LV cavity was detected in all patients, but its decrease was present only in HCM cases. The contractility of the myocardium was impaired in all the patients examined. Disturbances of the myocardial perfusion were the most pronounced in NKMP and DCMP patients. Signs of fibrosis were detected in most patients, but HCM patients. In 40% of CM patients, scintigraphic signs of inflammation were determined. In 17% of all examinations there was noted hyperperfusion of the right ventricular myocardium. The authors believe myocardial tomoscintigraphy to be the unique method for analyzing myocardial viability in various forms of cardiac pathology that can be used for the evaluation of the effectiveness of the treatment.