Specific hemodynamic stresses (flow, volume, pressure) cause distinct histological patterns of valvular thickening in congenital heart anomalies, except in certain chromosomal anomalies.
A total of 787 cases with various congenital heart anomalies was histopathologically studied for valvular thickening, especially from the view point of response to mechanical stimulation (hemodynaqic changes). Macroscopically, both atrioventricular and semilunar valve leaflets showed difhse and rugous thickening of the body with thickened chordae tendineae or widened noduli Morgagni and/or Arantil and separation of the commissure in cases with increased blood flow or, enlarged volume. They showed localized thickening at the distal ends including the line of closure and prominent noduli in cases with increased pressure. Histological examination revealed that the increased flow made the proximalis thickened, the increased volume made the Abrosa thickened and the increased pressure made the spongiosa hypertrophied. The combined hemodynamic stresses made any of the combination of the 3 types of morphological change. Some of the connective tissue disease such as gargoylism and Marfan syndrome showed the same rule superimposed to their basic disorder. Crasy valvular changes associated with chromosome anomalies such as mongolism, 15 and 18–trisomy were exceptionally out of the rule of hemodynamic changes.
Ryozo Okada (Mon,) studied this question.