Electronmicroscopic observations regarding the presence of natriuretic granules in the ventricle of patients with cardiopathies.

As part of studies regarding the human myocardium biology in hereditary and acquired cardiopathies, we showed the presence of natriuretic granules (NG) not only in atriums but also in ventricles, in ten of our cases with intraoperative myocardium biopsies. Ultrastructurally, the natriuretic granules occur in lesions produced by hemodynamic and consecutively hypoxic disturbances, being present at the ventricular level, too, both near the Golgi apparatus that secrets them, and diffusely, in cardiomyocytes, beneath the altered organelles and phagolysosomes. Their aspect in similar in cardiac malformations (DSIA. Fallot tetralogy) and in mitral valvulopathies, their abundance being in connection with congestive heart failure (CHF). Although predominant in CHF class I and II, they occur also in the severe decompensations class III and IV, being perhaps felt at the cardiac level as they are released in the blood. This phenomenon is expressed by electronmicroscopic presence of natriuretic granules in the subsarcolema and the increased plasma level of natriuretic peptide, according to biochemical findings reported in the literature. They produce a vasodilating, diuretic, natriuretic effect, contributing to blood pressure regulation and testifying in the neuroendocrine role of human myocardium.