Clinical significance of myocardial deformation of a left ventricle in children with hypertrophic cardiomyopathy

Purpose: to evaluate the clinical significance of left ventricular myocardial deformation indicators, their relationship with the degree of heart failure and left ventricular hypertrophy in children with hypertrophic cardiomyopathy (HCM). Materials and methods. 61 patients with primary genetically confirmed asymmetric HCM aged 7 to 17 years underwent a comprehensive clinical and echocardiography. Echocardiography determined indicators of left ventricular systolic function: ejection and shortening fractions, global longitudinal, circular and radial myocardial deformations and deformations rates. The assessment of myocardial hypertrophy of left ventricular segments was performed taking into account absolute values in systole and diastole depending on age, recalculated per standard deviation units in the population (Z-score factor). Results. A more pronounced degree of heart failure, a decrease in ejection and shortening fractions, and indicators of left ventricular myocardial deformation were established in all children with non-obstructive and obstructive forms of HCM and an extreme degree of myocardial hypertrophy, in contrast to the non-obstructive form of the disease with a less pronounced degree of hypertrophy. An earlier decrease in myocardial deformation indices was revealed in comparison with ejection and shortening fractions, longitudinal deformation and its speed in comparison with radial and circular, their speeds. Conclusions. 1. In children with HCM and extreme degrees of left ventricular myocardial hypertrophy, compared with mild and moderate hypertrophy, a more pronounced degree of heart failure is observed, which is accompanied by a decrease in left ventricular systolic function. Among them, a decrease in myocardial deformation rates and their velocities is more sensitive compared to left ventricular ejection fractions and shortening. 2. Reduction of left ventricular myocardial deformation in children with HCM depends on the degree of hypertrophy. The earliest, manifesting itself even with a mild degree of hypertrophy, is a decrease in longitudinal deformation and its speed compared to circular and radial deformations and their speeds. 3. Determining the indicators of left ventricular myocardial deformation in children with HCM in comparison with the degree of myocardial hypertrophy is of great clinical importance in assessing the systolic function of the left ventricle to optimize administration tactics and timely treatment of the disease.