Perioperative myocardial protection with the calcium antagonist diltiazem.

The effect of the calcium channel blocker, diltiazem, on cardiac performance was examined in 90 patients who underwent isolated aortic valve replacement for aortic valve diseases with marked left ventricular hypertrophy. The patients were randomly assigned to one of five groups dependent on the treatment plan with diltiazem: group 1, 5-day preoperative treatment with oral administration of 60 mg diltiazem 3 times daily, 10 mg diltiazem intravenously as a bolus dose before the beginning of the cardiopulmonary bypass, and 5 mg diltiazem intravenously 10 min before removal of aortic clamp; group 2, 5-day preoperative treatment with oral administration of 60 mg diltiazem 3 times daily; group 3, 10 mg diltiazem intravenously as a bolus dose before the beginning of CPB and 5 mg 10 min before removal of the aortic clamp; group 4, 15 mg diltiazem in 1000 ml cardioplegic solution, given as additive; group 5, control group not receiving diltiazem. All operative procedures were performed in an identical manner with an average cross-clamping time of 57.

Incidences and surgical aspects of cardiac myxomas in Bulgaria.

63 patients with cardiac tumors underwent operative treatment between January 1970 and December 1988. Three additional patients refused the operation, despite the large left atrial myxomas and obstruction of the mitral valve, recognized by echocardiography. 62 patients had benign tumors: the only malignant neoplasm was a fibrosarcoma, originating from the right ventricle.

Cytomorphology of atherosclerosis: smooth muscle cells in formation and regression of atherosclerotic lesions.

Human fibrous atherosclerotic plaques from the superficial femoral artery, obtained at surgery and autopsy, were examined by transmission electron microscopy and immunofluorescence microscopy for antibodies to intermediate filament proteins (IF) vimentin, and desmin. The results showed that smooth muscle cells (SMC) of human fibrous plaques accounted for the predominant cell type, demonstrating a spectrum of phenotypes, with prevalence of cells with prominent rough endoplasmic reticulum, implying a synthetic phenotype. In regressing atherosclerotic plaques, contractile SMC were predominant and, along with them, few SMC with abundant cellular organelles were observed, displaying ultrastructural manifestation of collagen phagocytosis.

Involvement of smooth muscle cells in collagen degradation in the postpartum uterus.

Ultrastructural study of gravid and postpartum involuting human uteri revealed a number of cells containing collagen fibrils in their cytoplasm. In gravid uteri these cells could be identified as macrophages and fibroblasts; in the postpartum uteri smooth muscle cells (SMC) were also found, containing cytoplasmic collagenous vacuoles. The morphology of intracellular collagen in SMC was similar to that observed in macrophages: fragments of banded collagen fibrils with a diameter corresponding to that of extracellular collagen were located within structures considered to be phagosomes.