[Idiopathic mitral subvalvular aneurysm. Report of a case and review of the literature]. / Aneurisma subvalvular mitral idiopático. Informe de un caso y revisión de la literatura.

An unusual type of annular, subvalvular left ventricular aneurysm is described for the first time in a 64 years-old mexican woman. The pathological characteristics are similar to those cardiac aneurysms of unknown etiology described in African negroes. In this paper, we review the clinical features, diagnostic difficulties and discuss possible etiologic factors related to this condition.

Aneurisma subvalvular mitral idiopatico. Informe de un caso y revision de la literatura. / Subvalvular mitral idiopathic aneurysm: report of a case and review of the literature

Se decribe por primera vez en nuestro medio, la existencia de un proceso patologico conocido como aneurisma anular subvalvular mitral, en un paciente del sexo femenino de 64 anos de edad. Las caracteristicas anatomopatologicas del presente caso son semejantes a las observadas en cierto tipo de aneurismas de alta prevalencia en negros africanos. Se describen asimismo, las manifestaciones clinicas y los problemas de diagnostico a que dan lugar.Se discuten los posibles factores etiologicos relacionados con dicha alteracion

[Nonspecific aorto-arteritis. Anatomo-pathological study of 18 cases]. / Aorto-arteritis inespecífica. Estudio anatomopatológico de 18 casos.

The present study comprises a pathological review of 18 necropsy cases with nonspecific aorto-arteritis (Takayasu's disease), autopsied at the Instituto Nacional de Cardiología of Mexico up to 1976. There were 11 females and 7 males with an average age at the time of death of 21.5 years. A comparison according to the distribution and extention of arterial lesions disclosed that our cases are often less classical than those described from Japan. The principal arterial changes were stenosis, occlusion, dilatation and aneurysm formation in the aorta, its branches and main pulmonary artery. More often than not the aorta was extensively involved. The aortic arch syndrome and renovascular hypertension were almost equally present in this serie and an unusual high incidence of coronary artery involvement (33%) leading to myocardial infarction (50%) also was observed. The significance of the intrapulmonary vascular changes in Takayasu's arteritis is discussed.

Intracellular collagen fibrils in prolapsed ("floppy") human atrioventricular valves.

Ultrastructural study of prolapsed atrioventricular valves from five patients, one of whom also had the Marfan syndrome, disclosed granular cells that were characterized by numerous membrane-bound, electron-dense inclusions resembling those in the Hurler syndrome. Collagen fibrils were present within some of these inclusions. The intracellular collagen deposits may form as a consequence of abnormal interactions between newly secreted collagen and acid mucopolysaccharides.

Striated membranous structures in human hearts. An ultrastructural study.

Straited membranous structures (SMS), which consisted of sheets or ribbons of 130 to 220 A in thickness, showed variable patterns of periodic substructure, and resembled SMS described in renal and ocular tissues in various diseases, were found in extracellular locations in a) mitral valve (2 patients) and tricuspid valve (1 patient) of 2 patients with mitral valvular prolapse, b) mitral valve and femoral artery of 1 patient with Marfan's syndrome and prolapsed mitral valve, and c) myocardium (2 patients) and thickened endocardium (3 patients) of 3 patients with congenital heart disease associated with muscular obstruction to right ventricular outflow. Striated membranous structures measured up to several microns in diameter, often were highly folded and convoluted, and sometimes appeared circular in outline. Some SMS measured from 130 to 150 A in thickness and had indistinct edges and poorly defined periodicity. The majority of SMS, however, had greater thicknesses, in the range of 200 A, and a periodicity characterized by alternating light and dark bands with a spacing that varied from 100 to 160 A. The structures were associated with thickened basement membranes, elastic fibers, and membrane-bound bodies of the type thought to be involved in elastogenesis. Evidence available suggests that SMS results from an unusual pattern of arrangement of a component, possibly Type IV collagen, of basement membrane material.

The heart in the Hurler syndrome: gross, histologic and ultrastructural observations in five necropsy cases.

Clinical and morphologic features of the cardiovascular system are described in five necropsy patients with the Hurler syndrome. In all five patients the coronary arteries, four cardiac valves, mural endocardium of all four chambers, myocardial walls and aorta were affected in a characteristic manner. All of these sites contained large clear cells known as Hurler cells (readily visible by light microscopy). In addition, granular cells were observed in semi-thin (1 mu) sections and by electron microscopy in the coronary arteries, atrioventricular (A-V) valves and in myocardial interstitium. These latter cells appear to produce collagen in an abnormal way and are probably responsible for the heavy deposits of collagen in the cardiovascular system of patients with the Hurler syndrome. In the cardiac muscle cells, in smooth muscle cells of the coronary arteries and in fibroblasts, wherever located, deposits of acid mucopolysaccharides and glycolipids usually were also observed. The acid mucopolysaccharide deposits were observed easily with light microscopy except in the cardiac muscle cells where they were seen only with electron microscopy. The glycolipid depositis, observed only on examination of 1 mu thick sections or with electron microscopy, have not previously been observed in coronary arteries or in myocardial cells. The infiltration into the heart by these cells and deposits in all five patients resulted in severe narrowing of the extramural coronary arteries, considerable thickening of the cardiac valves (the left-sided more than the right-sided valves), generalized thickening of mural endocardium and "stiffening" of the myocardial walls. Thus, the cardiovascular lesions in the Hurler syndrome are specific and life-threatening.

Intracellular collagen fibrils in cardiac valves of patients with the Hurler syndrome.

Ultrastructural study of thickened mitral and tricuspid valves from three patients with the Hurler syndrome disclosed collagen fibrils located within membrane-bound cytoplasmic dense bodies in small granular cells. These cells, which differ morphologically from the clear cells containing mucopolysaccharide deposits, are considered to be fibroblasts in advanced stages of degeneration. It is postulated that the elevated concentrations of dermatan sulfate in Hurler's disease lead to an abnormally high synthesis of collagen and to its polymerization in intracellular loci.