Morfometria do miocárdio humano em indivíduos senis Morphometry of human myocardium in senile individuals

OBJETIVO: Realizar uma avaliação quantitativa nas células do miocárdio humano de indivíduos senis, nas regiões ventriculares direita, esquerda e septal. MÉTODOS: Foram utilizados cinco corações de cadáveres de indivíduos sem enfermidades cardíacas, de ambos os sexos, com idade entre 67 e 87 anos. Foram avaliados os seguintes parâmetros: área da secção transversa unitária do miócito (a o mioc); comprimento do perímetro unitário do miócito (l o mioc); volume unitário do miócito (v o mioc); densidade volumétrica dos miócitos (Vv mioc); número de miócitos por unidade de volume (Nmm &#094;³mio). Na análise estatística utilizou-se o teste "t" de Student. RESULTADOS: A análise das diferenças (pOBJECTIVE: To carry out a quantitative assessment in human myocardium cells of senile individuals, in right, left and septal ventricular regions. METHODS: Five hearts from corpses of individuals without heart diseases, of both sexes, with age between 67 and 87 years old were used. The following parameters were assessed: myocyte unit cross section area (myoc. a o); myocyte unit perimeter length (myoc. l o); myocyte unit volume (myoc. v o); myocyte volumetric density (myoc. Vv); number of myocytes per volume unit (Nmm &#094;³myoc.). The t-test of Student was used in statistic analysis. RESULTS: The analysis of differences (p < 0.05) among right (RV), left (LV) and septal (S) ventricular regions of human heart showed that myoc. a o values were lower in RV (1.51 &plusmn; 0.10 &micro;m²) and in S (1.55 &plusmn; 0.07 &micro;m²) in relation to LV (1.84 &plusmn; 0.24 &micro;m²). Values of myoc. l o were also shown lower in S (5.11 &plusmn; 0.46 &micro;m) comparing to LV (6.2 &plusmn; 0.97 &micro;m). Likewise, myoc. v o and myoc. Vv showed lower values in RV (88.75 &plusmn; 25.37 &micro;m ³; 0.39 &plusmn; 0.03%) in relation to LV (122.41 &plusmn; 16.31 &micro;m ³; 0.41 &plusmn; 0.01%). CONCLUSION: Results obtained show that there may be changes in dimensions of left ventricular wall myocyte cell during senescent stage. However, those differences are subtle and seem to mean the adjustment of tissue to functional changes that install along life