Журнал «Здоровье ребенка» 8 (59) 2014

Introduction.

Prevalence of mitral valve prolapse  (MVP) in children's age according to researchers makes up from 2,4  % to 14 %. In such patients  in progressing  MVP,  development  and increase in frequency  of  such dangerous complications as infectious endocarditis, cardiac dysrythmia thromboembolism, ischemic stroke, sudden death, formation  of chronic  mitral  insufficiency  are  possible with age, all mentioned demands  long treatment  and supervision.

The most informative in diagnostics  of MVP is echocardiography method. Despite  improvement  of echocardiographic diagnostic criteria, now there are no uniform recommendations on classification and definition of MVP origin. Considering ambiguity in prognosis of MVP course depending on  its etiology, possibility of development of life-threatening  complications, formations of chronic cardiac insufficiency, it is expedient and timely to search  for further diagnostic criteria of different  etiopathogenetic variants of MVP origin in children.

Materials and methods.

With the purpose to determine  hemodynamic  and morphometric  features  of MVP of inflammatory and non-inflammatory  genesis in children by the data of  doppler-echocardiography (DopplerEchoCG) the analysis of 34 cases of  clinical  course of MVP in children at the age from 5 till 17 years is carried out. For  comparative analysis  2 groups of children  were distinguished: the first  group - 16 children  with MVP of non-inflammatory  genesis, the second one – 18 children  with MVP of inflammatory genesis. 

Criteria of inclusion in the 1-st group were: child’s age of more than 5 years, existence of stigmas of non-differentiated dysplasia of connective tissue, absence of congenital heart disease, lack of a carditis in the anamnesis, absence of echocardiographic (EchoCG) signs of endo- and myocarditis. Criteria of inclusion in the 2-nd group were: infectious myocarditis in the anamnesis, existence of EchoCG  signs of inflammatory lesion of  myocardium, absence of congenital heart disease.

Morphometric indicators of heart, parameters of intracardiac hemodynamics were measured with the help one - and two-dimensional EchoCG, impulse DopplerEchoCG on the ultrasonic scanner by a standard technique. Determination of ultrasonic density of the mitral valve and subvalvular structures was carried out by means of measurements of ratio of ultrasonic density in standard zones (valve ring,  edge of septal cusp) during digital computer processing of echocardiograms.

Results.

In the analysis of EchoCG indicators in children with MVP some distinctions in groups  were revealed. Average sizes of diameter of the left ventricle, the left auricle and the right ventricle which were normalized by the body area, had no essential distinctions in the groups (p> 0,05). Thus, in children of the 2nd group   frequency of cases of increase of the left ventricle cavity (6,3 % and 16,7 %, p> 0,05), was bigger and the increase of the right ventricle cavity – essentially bigger (37,5 % and 61,1 % respectively, p <0,05) this was explained by existence of chronic tonsillitis in children. In children of the 2nd group the increase in thickness of posterior wall of the left ventricle, interventricular septum relatively the norm (31,2 % and 61,1 %, 56,3 % and 94,4 % respectively, p <0,01) was revealed more often. In children of the 2nd group mass of myocardium of the left ventricle on average was authentically bigger (p <0,01), this testified to  hypertrophy of myocardium which was revealed in 61 % of cases.  Myocardial contractivity with the same frequency was lowered in the 1-st (31,3 %) and the 2nd (22,2 %) groups of children though this did not influence indicators of the central hemodynamics. Children with MVP in both groups in 93,8 % and 100 % of cases had  transmitral regurgitation of different degree. In children of the 2nd group MVP was accompanied with regurgitation of the ІІІ degree reliably more often. (83,3 % and 37,5 % of cases, p <0,001). Less considerable regurgitation (І - ІІ degrees) which was hemodynamically not significant was observed more often in the 1st group of children. It was revealed bigger frequency of  tricuspid regurgitation of the ІІІ degree in children of the 1-st group (19 %), this was explained by the existence  of  syndrome of connective tissue dysplasia in all cases. In such children regurgitation was registered simultaneously on mitral and tricuspid valves.

Normal ultrasonic density of the mitral valve cusps authentically more often was revealed in children of the 1st group: anterior cusp - in 37,5 % against 11,1 % of cases in the 2nd group (p <0,01); posterior cusp - in 62,5 % against 22,1 % of cases in the 2nd group (p <0,01).

Increase of ratio of ultrasonic density of both cusps of the mitral valve in the zone of  mitral ring was revealed in 37,5 % of children of the 1st group and in 50 % of children of the 2nd group, thus  children of the 2nd group in 55,5 % of cases had a considerable increase of ultrasonic density. Similar deviations of ultrasonic density were revealed and from the side of edge of anterior and posterior cusps of the valve. In both groups of children increase of ultrasonic density of anterior cusp of the mitral valve (76,9 % and 86,7 % of cases, respectively) prevailed. In children with MVP of inflammatory genesis in prevailing number of cases  increase of ultrasonic density of anterior - 83,3 % and posterior - 94,4 % of papillary muscle of the left ventricle, in the main of considerable and sharp degree (76,5 %), was revealed; this was regarded as a symptom of the suffered myocarditis.

The thickening of anterior cusp of the mitral valve more than the norm (more than 3 mm) was revealed reliably more often in children of the 2nd group  - 72,2 %  and 50 %, correspondingly (p <0,05). Authentically less often in both groups  thickening of posterior cusp of the mitral valve was revealed (p <0,05), thus the percent of cases of thickening of posterior cusp  in groups  was approximately  the same: 31,3 % in the 1st group and 44,4 % - in  the 2nd group  (p> 0,05).

Conclusions.

The carried-out researches made it possible to reveal characteristics of MVP of inflammatory genesis which can be obtained by means of EcoCG examination. In children with a prolapse of the mitral valve of inflammatory genesis authentically more often thickening of myocardium wall and myocardium mass were revealed, this testified  to hypertrophy of the left  ventricle; more often prolapse of ІІ-ІІІ degrees  was revealed; authentically more often mitral regurgitation of ІІІ degre leading to development  of chronic  cardiac  insufficiency  was noted. In 83,3-94,4 % of cases substantial  or sharp increase of ultrasonic  density of papillary  muscles  of the left ventricle was revealed, this was not  characteristic for a prolapse of non-inflammatory genesis. In all children with a prolapse of the mitral valve increase of ultrasonic density of anterior cusp prevailed. The thickening of anterior cusp by  more than 3 mm authentically  more often was observed in children  with  prolapse of the mitral valve of inflammatory genesis.