Labā priekškambara audu morfoloģiskās pārmaiņas dažādu iedzimtu sirdskaišu gadījumos: pilotpētījums

The incidence of children with congenital heart diseases is 8 children per 1000 new-borns.
Morphological and histochemical myocardial changes of congenital heart diseases are still being
researched. One of the most important pathological events in myocardium is apoptosis which has been
associated with ischemia.
Tissues from five children were used, two with cyanotic and three children with acyanotic
congenital heart disease, whose surgery was performed between the ages of 16 days to 14 months.
To evaluate different pathological changes in myocardium, such factors as vascular endothelial
growth factor (VEGF) and endothelin (ET) were used, which are indicators of vasculogenesis and has been
associated with ischemia in case of congenital heart disease. Protein gene product 9.5 (PGP 9.5) was used
to evaluate the innervation of myocardium. Atrial natriuretic peptide (ANP) as with chromogranin (CHR)
are indicators of homeostasis in the myocardium and the elevation of these factors is associated with
ischemia in the heart in children with congenital heart disease. Terminal deoxynucleotidyl transferase
dUTP nick end labelling (TUNEL) was used for detection of apoptosis.
Cardiomyocytes demonstrated different sizes, with vacuoles and in one case ingrowth of connective
tissue fibres among the myocardial tissue was detected. Almost all cases showed VEGF in numerous
cells, but ET was seen in few endotheliocytes or was not detected at all. In all cases, abundant number of
PGP 9.5-containing fibres was observed. ANP varied from few to numerous numbers of immunoreactive
cardiomyocytes, while CHR was detected in numerous cells in all cases. TUNEL showed a large quantity
of apoptotic cells with an average value of 186 ± 44.4.
Large number of VEGF containing endotheliocytes in case of congenital heart disease correlates with apoptosis.
Highly expressed neuropeptides containing innervation were evaluated as reaction of myocardium homeostasis impairment (ischemia and apoptosis).
The number of ANP and CHR positive cells gave evidence about partially disturbed but still compensated homeostasis of myocardium in children with congenital heart diseases.