[The DNA and protein content of atrial cardiomyocytes and the size and ultrastructure of the cardiomyocytes in children with congenital heart defects].

Right atrium myocytes were obtained during open heart surgery from 4 patients with atrial septal defect, and from 1 patient with Fallot's tetrad, aged from 3.5 to 6 years. DNA and total protein contents were measured consecutively in isolated cells using two-wave-length scanning cytophotometry following double staining after Feulgen and with naphthol yellow S. All the biopsies contained polyploid myocytes: the number of 4c cells varied from 18 to 41%, that of 8c cells from 0 to 4%. The average values of cells area and protein content for tetraploid cells were 1.5 times higher that for diploid ones. In all the cases normal and little changed myocytes were dominating (69-91%). The highest number of cells with moderate and severe degenerative changes was registered in the cases of maximum degree of cell hypertrophy and polyploidization.