[Cardiomyocyte in valvular cardiopathies. Comparative morphometry of myofibrils and mitochondria. Functional...

Twenty-four endomyocardial biopsies performed during surgical correction of valvulopathies were compared with ventricular function. Patients were divided into three groups: group I without anomalies of ventricular function, group II with a slight decrease of the ventricular ejection fraction, group III with a low ventricular ejection fraction. Morphometric analysis was carried out using electron microscopic photographs and an image analyser. The results were correlated with those of functional studies. In patients of the second group, the small number of mitochondria with respect to the increased myofibrillary area seemed to indicate mitochondrial dysfunction. In patients of the third group, alterations of myocontractility expressed a myofibrillary deficiency unable to be corrected by the multiplication and the increased exchange areas of mitochondria.