Myocardiodystrophy in children: Diagnosis and treatment
Sixty children with myocardiodystrophy were examined. Common and local changes in repolarization processes were revealed in two and one thirds of cases, respectively; ST—T abnormalities were adrenal-dependent in 60% of the children and metabolism-dependent in 40%. ECG impairments in repolarization processes were transient in most cases, by becoming worse during exercise, and accompanied with the signs of sinus node dysfunction in one-fourth of the children. Analysis of heart rate variability revealed excessive sympathetic influences on heart rhythm in one third of the children with myocardiodystrophy. Three types of hemodynamic rearrangement were identified during graded exercise testing; these included adaptive, dysregulatory, and disadaptive, which served as a manifestation of occult heart failure. Measurements of the blood levels of lactic and pyruvic acids were shown to be of important diagnostic value for the early diagnosis of impaired cellular energy processes. Determination of the cytochemical activity of mitochondrial enzymes in peripheral blood lymphocytes could evaluate the processes of oxidative phosphorylation occurring in the mitochondria. It was demonstrated that elevated succinate dehydrogenase levels were compensatory and the decrease in this enzyme reflected a significant impairment in energy-rich processes and correlated with the signs of lower myocardial functional activity. Based on the study results, the authors have proposed an algorithm for diagnosing myocardiodystrophy and determining its stages. They also have developed the differentiated treatment system for myocardial dystrophic lesions, which is aimed at preventing heart failure.