Biomedical subjects
Publications and source records attributed to C Velican.
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In an unselected population sample of Bucharest, including 536 subjects (284 males and 252 females) aged up to 40 years, sex appeared as one of the most important factors influencing the pattern of coronary artery growth and remodelling, as well as the pattern of atherosclerotic involvement. The internal elastic membrane of the female coronary arteries of neonates, children, juveniles and adolescents manifested a lesser tendency to fragment, to interrupt and to exhibit elastolysis than did the corresponding internal elastic membrane of male subjects. In the anterior descending and circumflex arteries, female subjects had less intima than males of similar age. Women developed the first atherosclerotic plaques a decade later than men and at a similar age showed fewer atherosclerotic plaques and atheromas. These sex differences were statistically significant for the anterior descending and circumflex arteries, but not for the right coronary artery. During adulthood, the number of women with a three vessel involvement was half that of men. In successive age groups, the degree of luminal narrowing by atherosclerotic plaques was constantly and consistently lower in female than in male subjects.
Gross dissection of the coronary arteries of 566 subjects aged 0--45 years from an unselected population sample of Bucharest revealed the presence of a similar anatomical branching pattern in 58% of cases. Starting from this common type of distribution of coronary arteries, some minor deviations were detected coexisting with a thicker intima, a more rapid onset and evolution of atherosclerotic plaques, and a more important degree of luminal obstruction. Among the 15 minor deviations described in this paper, 3 were constantly associated, 9 only occasionally associated and 3 not associated with an accelerated atherosclerosis. The most important of these atherogenic deviations was present in 29% of cases or in 1 out of every 3 or 4 subjects. In essence, these deviations consisted of an excessive increase in external diameter and length of the left coronary arterial system, coexisting with an underdeveloped right coronary arterial system, or vice versa. The atherogenic deviations from the common type of distribution of the coronary arteries seemed to represent an important genetically transmitted risk factor for coronary heart disease.
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Intimal histolysis begins, histochemically, with the removal of sulfate esters of acid mucopolysaccharides and of sialic acid of glycoproteins. The disappearance of the steric hindrance exerted by these acid groups if followed by the degradation of the ground substance and fibres. Certain particular aspects of this degradation are presented.
A study was carried out on the prevalence and distribution of eccentric and concentric atherosclerotic plaques in the coronary arterial tree of 916 unselected apparently healthy subjects who died from accidents and of 150 selected patients who died from coronary heart disease. The results show that the percentages of eccentric and concentric plaques vary with age, sex, anatomical branching pattern and cause of death; there are also differences between major coronary arteries and main branch vessels. In addition to eccentric and concentric plaques, we revealed the existence of mixed (both eccentric and concentric) plaques, mainly located at branch points.
An attempt was made to reconstruct the succession of structural changes which lead to the onset of fibrous plaques in the coronary arteries of children. The results show that certain branch pads or cushions act as precursors of the first fibrous plaques. The conversion of branch pads into atherosclerotic lesions includes edema, histolysis (elastolysis, collagenolysis, ground substance depletion and degenerative cell changes) and in a final step nodular proliferation of smooth muscle cells and abundant neoformation of collagen fibers. This conversion is followed by both reorganization and homogenization of the preexisting heterogeneous microarchitecture. The intermediate steps of pad conversion into atherosclerotic lesions were revealed in 4% of children 1 - 5 years old, 14% of children 6 - 10 years old and 24% of children and juveniles 11 - 15 years old; small, non-raised fibrous plaques were already present in 2% of children 6 - 10 years old and in 4% of children and juveniles 11 - 15 years old.
The coronary arterial beds from more than 1200 subjects aged 1 to 65 years were investigated by both histopathological, histochemical and morphometric methods. Light microscopic aspects were analysed to reveal if plaque development and progression toward obstructive lesions were associated with arterial wall changes, particularly of the intimal connective tissue adjacent to lesions. Six patterns of plaque development in the coronary arterial tree were delineated, emphasis being placed on the observation that the onset and progression of plaques frequently appeared independent of arterial wall changes, in contrast to fatty streaks, gelatinous lesions, intimal necrotic areas, incorporated microthrombi and intramural thrombi. Our results support the view that plaques develop and progress on their own, superimposed on a preexisting arterial wall microarchitecture.
A postmortem study was carried out on the whole coronary arterial bed of 430 selected apparently healthy subjects, aged 38 to 65 years, in an effort to reveal the influence exerted by coronary heart disease risk factors (CHDRFs) on the development of coronary obstructive plaques. A clear positive correlation was found in 31% of cases and in more than 50% of 28 selected topographic sites of the coronary arterial bed. On the other hand, the subgroup without CHDRFs also exhibited severe coronary narrowings. Each major CHDRF seems to exert its particular action on selected regions of the coronary arterial bed: proximal or intermediate segments of the major coronary arteries; branching points; nonbranched areas; vessels supplying the conduction system, etc.
The paper reports both on the new directions and trends and on the present stage of several controversial problems, for a better understanding of etiopathogenesis prevention and treatment of ischemic cardiopathy, a priority problem of the public health in Romania.
The paper reports and assesses the most topical data having led to delimiting the asymptomatic myocardial ischemia as the most precocious form of manifestation of ischemic cardiopathy. The role of asymptomatic myocardial ischemia involvement in angina pectoris, myocardial infarction and serious arrhythmias leading to sudden cardiac death are also underlined from the viewpoint of prognosis severity. Likewise, the authors discuss; the prevalence of asymptomatic myocardial ischemia as a distinct manifestation form of myocardial ischemia; the way of selecting the cases; the anti-ischemic treatment that gave good results in diminishing morbidity and mortality induced by ischemic cardiopathy.
A study of the prevalence of thick intimas and of obstructive lesions in the vessels supplying the conduction system of the heart (first septal artery, sinus node artery, atrioventricular node artery, posterior descending artery) was carried out on both non-hospitalized and hospitalized subjects. A total of 932 cases aged 6 to 55 years were investigated. The age period of the onset of both intimal thickenings and atherosclerotic plaques, the percent of cases with intimal thickenings and atherosclerotic plaques in successive age groups and the highest value of the intima thickness/media thickness ratio, were recorded. Comparative data are presented between apparently healthy subjects who died of accidental causes and patients of similar age and sex, who died of coronary heart disease. Sudden cardiac death cases are presented showing as the most important lesion the obstruction of the sinus node and atrioventricular node arteries. The results point to a need for a more frequent routine examination of the vessels supplying the conduction tissue of the heart.