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Biomedical subjects

K R Anderson

Publications and source records attributed to K R Anderson.

At least 73 records · Page 4Linked to original sources
PubMed1982

Hypertension and sudden cardiac death.

In order to investigate the role of hypertension in prehospital sudden cardiac death, the heart weights of 223 subjects selected from 2140 autopsy examinations were compared. The cases were selected in order to eliminate known distracting causes of cardiomegaly. The heart weights of 40 male victims of prehospital sudden cardiac death were significantly heavier than those of similar aged individuals dying of noncardiac causes. The latter control group included both subjects with severe coronary atherosclerosis and subjects with minimal coronary atherosclerosis. This study suggests that cardiomegaly in male victims of sudden cardiac death probably reflects a high prevalence of undetected hypertension.

Adult↗
PubMed1982

Occlusive lesions of cardiac conducting tissue arteries in sudden infant death syndrome.

Cardiac conducting tissue from the hearts of 40 victims of sudden infant death syndrome was examined microscopically by serial section. In five hearts there were marked narrowing of the major artery supplying the atrioventricular node. In another there was similar narrowing of the artery supplying the sinus node. The arterial lesions were focal and characterized by cellular intimal thickening which severely narrowed the vessel lumen. This arterial anomaly may be a contributory factor in the pathogenesis of some cases of sudden infant death.

Arteries↗
PubMed1981

Human exposure to ferric sulfate aerosol: effects on pulmonary function and respiratory symptoms.

Twenty normal and 18 asthmatic human volunteers were exposed to ferric sulfate aerosol at a nominal concentration of 75 microgram/m3 (equivalent to 20 microgram iron/m3). The concentration and particle size distribution (2 micron mass median aerodynamic diameter; geometric standard deviation of 3) were selected to simulate worst case ambient conditions. Ferric sulfate was chosen for study because it is toxic, it is a respiratory system irritant, and increased use of coal and high sulfur fuel oils will lead to increased concentrations of iron and sulfate in ambient air. A double-blind protocol was followed in which each subject was exposed on two days, separated by about a three week period. The subjects were exposed to clean air (sham) on one day and to ferric sulfate aerosol on the other (exposure); the order of exposure was selected randomly. Neither the subjects nor the staff performing the clinical testing were informed as to the nature of the atmosphere on any given day. Pulmonary function tests were performed immediately before (pre) and after (post) each 2 hr sham or exposure period; this protocol included intermittent exercise. Pre- and post-exposure symptom score interviews were also administered. On the average, the two groups of subjects did not exhibit significant pre- to post-changes in total respiratory system resistance, forced expiratory flow/volume performance, and single breath nitrogen washout parameters. None of the subjects reported more than slight changes in symptoms during exposure. Five individuals showed small but significant decremental trends in pulmonary function; however, nine subjects tended to improve after exposure.

Adolescent↗
PubMed1981

Conduction tissue changes associated with enlarged membranous septum--a cause of sudden death?

We have studied four hearts in which enlargement of the ventricular membranous septum was associated with histological abnormalities of the atrioventricular conduction tissues. Two of the cases showed unusually formed penetrating and non-branching main atrioventricular bundles. These two cases plus one other also showed right-sided penetrating and main atrioventricular bundles. In addition these three cases all showed extensive fibre loss affecting the origin of the left bundle, which in one heart was further accompanied by fibre loss in the main bundle. The conduction tissue damage in the fourth case, though more extensive, was not as clearly related to the enlarged membranous septum since the heart in this case was also enlarged and dilated (congestive cardiomyopathy). Our findings, while obviously not conclusive, suggest that conduction changes in the presence of an enlarged membranous septum could be added to the list of causes of sudden cardiac death. They certainly indicate that when an enlarged membranous septum is found in cases of sudden death, histological study of the conduction system is desirable.

Adult↗
PubMed1981

Sudden death from occlusive disease of the atrioventricular node artery.

Non-atherosclerotic focal occlusive disease of the atrioventricular node artery was the only significant pathological lesion found at autopsy in 2 individuals aged 40 and 17 yr who died suddenly and unexpectedly. The cases were observed amongst 115 autopsies categorized as sudden cardiac death and performed during an 18 mth period. Occlusive disease of the atrioventricular node artery is a poorly documented entity of unknown aetiology and pathogenesis. We believe it is a more frequent pathological finding in sudden cardiac death than has been previously recognized and that it deserves more attention than it currently receives.

Adolescent↗
PubMed1980

Left main stem coronary artery dissection.

Left main stem coronary artery dissection is a rare cause of sudden death. This occurred in a previously asymptomatic 42-year-old white woman; clinical, arteriographic, and necropsy findings are described. Extrathoracic total body perfusion with isolated catheter perfusion of the dissected coronary artery using cold cardioplegic solution may be effective preoperative treatmemt.

Adult↗
PubMed1980

Histopathological specificity of hypertrophic obstructive cardiomyopathy. Myocardial fibre disarray and myocardial fibrosis.

The topography and specificity of fibre disarray and fibrosis in hypertrophic obstructive cardiomyopathy were determined in a histological study comprising 40 necropsy hearts--10 with hypertrophic cardiomyopathy, 10 with congestive cardiomyopathy, 10 with aortic valve stenosis, and 10 normal hearts. Seven standard regional sections were sampled from each heart and graded "double-blind" (tissue location and disease entity) for severity and extent of fibre dissarray and four distinct types of myocardial fibrosis. Statistical comparison of the severity and distribution of indices of fibre disarray and fibrosis within each group and between the normal and the disease groups showed that fibre disarray and fibrosis were qualitatively non-specific for hypertrophic cardiomyopathy. However, when fibre disarray was quantified (1) it was significantly increased in hypertrophic cardiomyopathy and allowed separation of hearts with hypertrophic cardiomyopathy from normal hearts and from those with congestive cardiomyopathy and aortic stenosis, (2) it did not vary significantly among sections of the left ventricle (that is, between the septum and the free wall) in hypertrophic cardiomyopathy, (3) it was closely associated with plexiform fibrosis, and (4) it varied independently of wall and septal thickness. Though the histogenesis of fibre disarray is unknown, it probably represents an exaggeration of a non-specific common pathway for many diverse pathophysiological processes.

Adolescent↗
PubMed1979

An experimental assessment of macroscopic enzyme techniques for the autopsy demonstration of myocardial infarction.

Experimental cardiac infarction produced in dogs by coronary artery ligation has been used to investigate the value of macroscopic histochemical enzyme loss in the diagnosis of myocardial infarction at post-mortem. Creative phosphokinase and non-specific dehydrogenase methods gave the best results but became positive only 5-6 hr after infarction. It is concluded that the method is of limited value in autopsy practice.

Animals↗
PubMed1979

Histopathological types of cardiac fibrosis in myocardial disease.

Myocardial fibrosis is a frequently observed pathologic finding. It is a common practice to differentiate macroscopic scarring and microscopic scarring, but there has been little attempt to distinguish the various types of interstitial fibrosis, and to determine their prevalence in different cardiac disorders. In this study, we have semiquantitatively assessed microscopic scarring, interfibre and perivascular fibrosis and a distinctive type of plexiform fibrosis. We examined ten hearts with congestive cardiomyopathy, ten with hypertrophic cardiomyopathy, ten with severe valvular aortic stenosis and ten normal hearts. Perivascular and interfibre fibrosis were quantitatively closely linked and most marked in the congestive cardiomyopathy and the valvular aortic stenosis groups. Plexiform fibrosis occurred maximally in the hypertrophic obstructive cardiomyopathy group, closely associated with myocardium exhibiting muscle fibre disarray. Our study demonstrates that although different types of interstitial fibrosis have particular associations with certain disease entities, the associations are not specific. The recognition of the prevalence of one or more types of interstitial fibrosis may, however, assist in the histopathologic diagnosis of certain myocardial disorders.

Adult↗
PubMed1979

Location and vascular supply of sinus node in human heart.

The exact location of the sinus node was determined in 25 infant hearts using reconstructive techniques. The sinus node was found to lie on the lateral aspect of the superior cavo-atrial junction in the great majority (22 hearts). In only 3 hearts was it found to straddle the summit of the crest of the right atrial appendage where it is popularly believed to be located. In the majority of instances a single artery supplied the node (in 11 hearts the artery approached posteriorly, and in 10 the artery approached anteriorly), though there was considerable variation in the exact anatomy of the arterial supply. Connections between the sinus node and atrial myocardium were diffuse and abundant but in no instances were tracts of specialised cells observed leaving the node and traversing any distance through the atrial wall. These findings are relevant to the sinus node dysfunction that may follow cardiac surgical procedures.

Arteries↗
PubMed1979

The cardiac conduction system in situs ambiguus.

The cardiac specialized conduction tissue was studied by serial sectioning in 13 cases of situs ambiguus. In four cases of right isomerism, we found paired sinus nodes in relation to a crista terminalis, and in each case a sling of conduction tissue between two atrioventricular nodes was present regardless of the ventricular morphology or cardiac position. In the cases with left isomerism, the sinus node was hypoplastic and abnormally located. We saw two types of atrioventricular conduction systems. In the three cases in which the morphologically right ventricle lay to the right of the morphologically left ventricle (presumed d-loop), a single atrioventricular bundle arose from a normally located atrioventricular node. In the five cases in which the morphologically right ventricle lay to the left of the morphologically left ventricle (presumed l-loop) and in the one case with a univentricular heart, paired atrioventricular nodes were present, linked or potentially linked by a sling of conduction tissue.

Atrioventricular Node↗
PubMed1979

Morphologic spectrum of Ebstein's anomaly of the heart: a review.

The rare and curious congenital malformation of the tricuspid valve known as Ebstein's disease or Ebstein's anomaly has been a subject of considerable interest to the cardiologist and the morphologist since its first description by Wilhelm Ebstein in 1866. With the evolution of various surgical techniques for the correction of this anomaly, a thorough understanding of the pathologic anatomy of the malformation assumes greater practical importance. It is now clear that although all hearts with Ebstein's anomaly have in common displaced basal insertions of the septal and posterior leaflets of the tricuspid valve, each case may be pathologically and hemodynamically unique. The malformed tricuspid valve may be incompetent, stenotic, or rarely, imperforate. It may be found in a left-sided tricuspid valve with inversion of ventricles. It is important that these individual variations be recognized so that the operative approach can be tailored to the particular variant of the malformation at hand.

Coronary Vessels↗
PubMed1979

The right ventricular myocardium in Ebstein's anomaly: a morphometric histopathologic study.

Ebstein's anomaly of the tricuspid valve is associated with right ventricular dilatation in approximately two-thirds of cases. Dilatation may be massive. It involves not only the right ventricular wall proximal to the tricuspid valve (atrialized ventricle) but also the right ventricle distal to the valve (funtional right ventricle), including the right ventricular infundibulum. For further definition of the pathogenesis of dilatation of the functional right ventricle (distal chamber), a morphometric histopathologic study was performed on 10 hearts with Ebstein's anomaly and 10 normal age-matched control hearts. In the group with Ebstein's anomaly, five hearts exhibited dilated ventricles and five did not. The study demonstrated that dilatation of the right ventricle in Ebstein's anomaly was associated not only with thinning of the wall but also with an absolute decrease in the number of myocardial fibers counted through the thickness of the wall from endocardium to epidcardium.

Dilatation, Pathologic↗
PubMed1978

Surgical significance of the coronary arterial anatomy in truncus arteriosus communis.

In truncus arteriosus communis, as in other anomalies of conotruncal development, the coronary arterial anatomy not only differs from that found in the normal heart but also is subject to unpredictable variations. A consistently distinctive pattern was found in roughly two thirds of 31 cases, a frequency approximating that with which a distinctive coronary arterial pattern occurs in complete transposition of the great vessels. Surgical injury to a major coronary artery was identified in 2 of the 30 hearts from patients with truncus arteriosus communis who died in the early postoperative period. Of particular significance are large branches of the right coronary artery crossing the upper anterior surface of the right ventricle to supply the anterobasal surface of both ventricles and the upper part of the interventricular septum. These arteries are at special risk in surgical procedures utilizing a conduit anastomosed to a right ventriculotomy.

Adolescent↗