Журнал «Здоровье ребенка» 4 (55) 2014

Objective: to study morphological and functional features of cardiac parameters and general hemodynamic in adolescents with myocardial pathology with various embodiments of diastolic dysfunction of the left ventricle of the heart.

Materials and Methods: A comprehensive survey of 41 children with myocardial pathology, including 22 - with heart rhythm disorders , 11 - with dysplastic cardiomyopathy, 7 - with primary hypertension and 1 - overvoltage infarction syndrome aged 13-18 . The study of morphological and functional cardiac parameters conducted by ultrasound in the "M" i "in" using 3.5 MHz probe on the unit "Sonoline-SL", the company "Siemens" by the standard method. LV diastolic function was studied in a pulsed Doppler transmitral flow with the mapping of access to the apical four-chambered heart. To identify the type of diastolic dysfunction (DD) was conducted tests with isometric exercise. During this process registration transmitral diastolic flow before and at the end of the third minute ascent of the lower limbs at an angle of 30-45 ° to the horizontal surface and holding it with a force equal to the weight of the leg.

Results and discussion: In assessing the morphological and functional cardiac parameters , in comparison with the control group , found a significant increase in the diameter of the aortic root (p < 0,05), a tendency to expand the diameter of the left atrium (p < 0,1), thickening of the posterior wall of the left ventricle (p < 0,01), as well as a significant increase in LV mass (p < 0,01) and LV mass index (p < 0,01). While systolic function did not differ from the control group and were within normal values. In the study of diastolic function parameters revealed that the temporal parameters (IVRT and DT) did not differ from the control group at the same time, the peak E was significantly lower in the group of adolescents with myocardial pathology (p < 0,01), as well as peak and, if the ratio E/A only had a tendency to increase (p < 0,1). These data indicate the formation of LV diastolic dysfunction in the studied adolescents. To clarify the type of diastolic myocardial dysfunction conducted tests with isometric tension. According to the results of this trial were randomized to teens three subgroups in accordance with aspect ratio E/A. The first subgroup includes those for which the ratio E/A was less than 1.5 cu secondarily - adolescents whose E/A is in the range 1.5 - 2 and the third - in which E/A was more than > 2.

In adolescents the first subgroup at the background isometric exercise (ID) occurs before all significant increase IVRT and DT, significant reduction wave E (p < 0.01) increase in wavelength A (p < 0.01), respectively, reduced ratio E/A (p < 0.05), indicating that the first type of diastolic dysfunction (first phase) - delayed LV relaxation. Diastolic reserve them in response to isometric exercise was only a few reduced (-33.8 %). In assessing cardiac parameters and general hemodynamic in response to isometric exercise significant expansion set the left atrium (LA) (p < 0.01) and a trend toward in overall hemodynamic formation hypokinetic variant circulation.

In the second subgroup, against the background of the sample with ID, reduction a tendency to increase (p < 0,1) DT, IVRT indicators have not changed. Was also a trend toward a decrease in the rate of left ventricular filling phase of the first (p < 0.1) increase the speed and reliable filling of the second phase (р < 0.01) and, as a consequence, a slight decrease ratio E/A (p < 0.1). However, it should be noted that, despite minor changes in the parameters of the diastolic function of this subgroup adolescents, diastolic reserve response IN more reduced (- 24.0 %), and confirms that the formation of these symptoms of type II diastolic dysfunction, etc. n. Pseudo normalization. In response to the ID of this subgroup of adolescents, there is some increase in performance as UO (p < 0.1) or CSO (p < 0.1), which preserves the normal ratio of the central and peripheral hemodynamic units, but it was a significant increase in the size of the left atrial (p < 0.05).

The third subgroup of adolescents with the PM on the background of ID marked tendency to increase IVRT, a significant increase (p < 0,01) DT, a decrease in both peak E and peak A, thereby improving the ratio E/A greater than 2.0 cu. (p < 0.01). Indicator DR in this group had a positive value (+8.61), which confirms the deeper diastolic dysfunction in this group of teenagers, as compared with other subgroups. Analysis of cardiac parameters studied in this group showed a significant increase in the diameter of the left atrium on the background of ID (p < 0.01), which is a proof of a violation diastolic left ventricular function of the heart. The ratio of central and peripheral hemodynamic units indicates the formation of a hyperkinetic version.

Thus, adolescents with myocardial pathology revealed a significant expansion of the left atrium, which can be regarded as one of the clinical signs of the formation of diastolic dysfunction of the left ventricle. In response to an isometric stress, there are three types of diastolic function of the left ventricle depending on the ratio E/A. The most pronounced signs of left ventricular diastolic filling were detected in the third group of teenagers, as evidenced by a significant expansion of the left atrium and increase the ratio E/A, and a positive value DR .