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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After introductory remarks about the flow phenomena in the human body (separation, dead waters, stagnation regions) and the model simularity conditions, the flow behaviour in arterial bifurcations at pulsatile flow are considered; they are accompanied by the formation of dead waters and secondary flows and therefore they give the danger of atherosclerosis. Then the flow pattern at arterio-venous anastomosis is interpreted with regard to the danger of thrombogenesis. At the selected example of ball prosthesis the flow pattern and the pressure loss of artificial heart valves (aortic as well as mitral valves) are described; the special behaviour of ball valves used as mitral valves is discussed critically. Finally in a view of contribution to the question of the flow-induced blood damage, in extended series of basic tests on models (orifices and perforated discs) the rate of hemolysis was measured depending on the flow; the tests were completed by measurements at rolling pumps, atria of a artificial ventricle and other parts. In order to try an explanation for the flow-induced hemolysis one starts from the influence of the hemodynamic shear stresses on the damage of the erythrocytes; hereby the effect of the frequently repeated passages of the red blood cells through a stenosis (e.g. regurgitation) should be taken into account.
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PMID:[Flow in natural and artificial organs and vessels (author's transl)]. 120 62

Anatomic and functional features of the normal and abnormal mitral valve are reviewed. Of 1,010 personally studied necropsy patients with severe (functional class III or IV, New York Heart Association) cardiac dysfunction from primary valvular heart disease, 434 (43%) had mitral stenosis (MS) with or without mitral regurgitation (MR): unassociated with aortic valve stenosis or regurgitation or with tricuspid valve stenosis in 189 (44%) patients, and associated with aortic stenosis in 152 (35%), with pure (no element of stenosis) aortic regurgitation in 65 (15%) patients, and with tricuspid valve stenosis with or without aortic valve stenosis in 28 (6%) patients. The origin of MS was rheumatic in all 434 patients. Of the 1,010 necropsy patients, 165 (16%) had pure MR (papillary muscle dysfunction excluded): unassociated with aortic valve stenosis or regurgitation or with tricuspid valve stenosis in 97 (59%) patients, and associated with pure aortic regurgitation in 45 (27%) and with aortic valve stenosis in 23 (14%) patients. When associated with dysfunction of the aortic valve, pure MR was usually rheumatic in origin, but when unassociated with aortic valve dysfunction it was usually nonrheumatic in origin. Review of operatively excised mitral valves in patients with pure MR unassociated with aortic valve dysfunction disclosed mitral valve prolapse (most likely an inherent congenital defect) as the most common cause of MR. Excluding the patients with MR from coronary heart disease (papillary muscle dysfunction), mitral prolapse was the cause of MR in 60 (88%) of the other 68 patients, and a rheumatic origin was responsible in only 3 of the 68 patients, all 68 of whom were greater than 30 years of age. Mitral anular calcification in persons aged greater than 65 years is usually associated with calcific deposits in the aortic valve cusps and in the coronary arteries. Because calcium in each of these 3 sites is common in older individuals residing in the Western World, it is most reasonable to view mitral anular calcification in older individuals as a manifestation of atherosclerosis. Mitral anular calcium appears to be extremely uncommon in persons with total serum cholesterol levels less than 150 mg/dl. Mitral anular calcium may produce mild MR and, if the deposits are heavy enough, MS.
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PMID:Morphologic features of the normal and abnormal mitral valve. 633 91

In sum, systolic dysfunction of the ventricle associated with left ventricular outlet obstruction and often with mitral valve regurgitation may be improved by myotomy, myomectomy, mitral valve replacement, and perhaps by the creation of left bundle branch block via DDD right ventricular pacing. Diastolic dysfunction of the ventricle may be improved by prolonging the diastolic filling period, shortening the isovolumic relaxation period with calcium channel blocking drugs, or perhaps by altering the atrioventricular activation time with a DDD pacemaker. The symptoms and complications of associated arrhythmias may be improved by medication, particularly with beta-blockers, which tend to stabilize the atrial rhythm and perhaps the ventricular rhythms. In treating patients with demonstrated ventricular arrhythmias, other antiarrhythmic agents may be helpful. (Table II summarizes the abnormalities, causes, and treatments of hypertrophic obstructive cardiomyopathy.) Epicardial coronary atherosclerosis is not rare in these patients, and arteriographic confirmation may lead to improvement by surgical bypass treatment. Since stroke volume is nearly fixed, cardiac output depends very much on heart rate. For this reason, each patient needs to receive the appropriate dosage of medications to achieve the optimal heart rate for his or her own physiologic state.
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PMID:Potential mechanisms of improvement after various treatments for hypertrophic obstructive cardiomyopathy. 764 95

Anomalous origin of the coronary artery can lead to angina pectoris, acute myocardial infarction or even sudden death in the absence of atherosclerosis. However, in Japan, this anomaly is usually treated medically rather than surgically. To clarify the clinical features of anomalous origin of the coronary artery in Japanese and the prognosis of such patients who are treated medically, we reviewed 56 patients with anomalous origin of the coronary arteries. The mean age of these patients was 55.9 +/- 11.5 years. Anomalous origin of the right coronary artery from the left sinus of Valsalva was seen most frequently (78.6%). In contrast, we found no cases of anomalous origin of the left coronary artery from the right sinus of Valsalva traversing between the aorta and the pulmonary trunk. A history of syncope (14.3%) and aorta regurgitation (21.4%) was frequent and serious complications during exercise stress testing occurred in 5 patients. These patients were treated medically, such as by limiting exercise or by the oral administration of medicine. During the follow up period (mean 5.6 +/- 4.2 years), death directly related to anomalous origin of the coronary artery was not found despite the lack of surgical treatment. Our results suggest that the prognosis of these middle-aged-to-elderly patients without atherosclerosis is relatively good, despite the lack of surgical treatment.
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PMID:Clinical features of prognosis of Japanese patients with anomalous origin of the coronary artery. 893 35

Hemodynamic imaging by phase contrast angiography was significantly accelerated by selective interpolation and segmentation in k-space using TURBO BRISK. The method was tested in vitro on three independent flowfields, representative of human blood rheology: a straight tube simulating the descending aorta, a curved tube simulating the aortic arch and a two-chamber orifice flow model simulating valvular regurgitation. The results were compared to data obtained by Laser Doppler Velocimetry (LDV) and showed good agreement. For the straight tube, the flow velocity obtained by five TURBO BRISK methods with increasing segmentation factors and corresponding time savings showed good agreement with LDV. For the curved tube, the velocity showed good general agreement with some differences in the decelerating part of the cycle, and in the low-velocity secondary flow structures. The orifice flow evaluation, the most time consuming case, was performed by the control volume method. It showed good agreement with actual flows through the orifice. Data acquisitions for TURBO-4 BRISK could be performed in 20s for each velocity component. The method shows promise for breath-hold acquisitions in clinical applications, including calculation of blood flow volumes through diseased arteries, measurement of blood backflow volumes through dysfunctional heart valves to time valve replacement operations, and evaluation of arterial wall shear stress, an important factor in the genesis of atherosclerosis.
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PMID:Hemodynamic evaluation with TURBO BRISK--a rapid phase contrast angiography technique. 1125 79

Renewed interest for aortic valve disease has evolved in recent years. Aortic valve replacement has become the second most frequent cause of cardiac surgery, following coronary bypass surgery. In addition, the etiologic and physiopathologic knowledge of this disorder has improved. In the present paper we analyze three aspects of the disease which are, at present, the subject of study and controversy: first, we discuss the possible relationship between degenerative aortic stenosis and atherosclerosis; second, the involvement of the aortic root in cases of bicuspid aortic valve; and third, the surgical indications in asymptomatic patients with either aortic stenosis or regurgitation.
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PMID:[New aspects in aortic valve disease]. 1153 84

This paper analyzes the results of the use of enoxaparin for anticoagulant therapy in reconstructions on the ascending aorta (AA) as compared to unfractionated heparin applied previously in the control group. Between 1986 and 2003 a total of 30 patients with AA aneurysms were operated on at the clinic. Insufficiency of the aortic valve with degree II-III regurgitation was present in 25 (83.3%) cases. Chronic dissection of the AA was identified in 10 (33.3%) cases. The patient's age varied from 24 to 52 years (mean 39 years). The etiological factors of AA aneurysm were: Marfan's syndrome (46.7% of cases), Erdheim's syndrome (26.7%), atherosclerosis (10.0% of cases); previous chest traumas were recognized in 16.6% of patients. All the patients were operated on under extra-corporeal circulation and moderate hypothermia. The patients were distributed into two groups. In the control group, eighteen patients were operated on. Anticoagulant therapy was carried out using unfractionated heparin i. v. in a daily dose 10-15 thousand units. Heparin injection was initiated on the first postoperative day and continued for 6.5 days on the average, with a progressive change over to the use of indirect anticoagulants. In the basic group, twelve operated patients were administered the anticoagulant enoxaparin s.c. in a daily dose 0.7-1.0 mg/kg bw. Enoxaparin therapy was initiated from the first postoperative day and continued for 8.9 days on the average, with a progressive change over to indirect anticoagulants. The postoperative lethality in the control group accounted for 22.2% (4 patients). In two cases, it was induced by heart failure and in two cases, by hemorrhagic complications. In the basic group, the beneficial results were achieved in 91.7%; no hemorrhagic complications were recorded. The data obtained allow the conclusion that the use of enoxaparin significantly facilitates the postoperative management of patients with AA aneurysms, providing for a controllable and safe anticoagulant effect.
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PMID:[The use of low-molecular heparins in reconstructive surgery of ascending aortic aneurysms]. 1562 90

A 73-year-old woman was referred to our hospital to investigate dilatation of an aortic arch which had been detected by a chest roentgenogram and severe aortic valve regurgitation detected by echocardiography. On admission, a computed tomography scan of the chest showed a large fusiform ascending aortic aneurysm. She had not shown any symptoms such as headache or polymyalgia rheumatica and had no significant coronary atherosclerosis. She underwent aneurysmectomy and reconstruction of the ascending aorta using cardiopulmonary bypass without aortic valve replacement, and pathological examination of the aneurismal wall revealed giant cell arteritis (GCA). Preoperatively, she did not have any temporal pain, and no signs of inflammation were detected serologically. Postoperatively, aortic valve regurgitation improved and she did well. However, three months after the surgery, she died suddenly due to the rupture or dissection of aorta. In the Japanese population, GCA is reportedly a rare cause of aortic aneurysm. However, retrospective studies show that GCA affects the aorta and that thoracic aortic aneurysm is a possible complication of GCA. In cases of the thoracic aortic aneurysms with unknown etiology, there is a possibility that GCA is the cause of the aortic aneurysm.
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PMID:Case of isolated thoracic aortic aneurysm as a manifestation of undiscovered giant cell arteritis. 1731 Aug 5

Although cardiac manifestations such as pericardial, myocardial, and valvular involvement are common in patients with systemic lupus erythematosus (SLE), coronary artery involvement is less frequent. Clinical manifestations of coronary artery disease in SLE can result from accelerated atherosclerosis, arteritis, abnormal coronary flow reserve, spasm, and thrombosis. In SLE, the classic valvular abnormality consists of noninfective, verrucous vegetation. Thickening of the leaflets due to inflammation followed by fibrosis is common, occurring in about 50% of patients, whereas vegetations are present in about 40%. Mitral valve involvement is most common, with valvular regurgitation more frequent than valvular stenosis. The tricuspid valve and the aortic valve may also be affected. Its frequency varies widely: 13% to 74% in the general population. We report a case of a woman with acute myocardial infarction and normal coronary arteries, who was subsequently diagnosed with Libman-Sacks endocarditis and SLE.
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PMID:Acute myocardial infarction in a patient with systemic lupus erythematosus and normal coronary arteries. 1740 1

Calcification of the aortic valve leads to stenosis or regurgitation or both. To clarify the mechanism of heart valve calcification, comparative studies using histological and ultrastructural examinations were performed of calcified aortic valves. These valves were obtained at valve replacement surgery from 11 patients with rheumatic aortic valvular disease (RAVD), 10 patients with degenerative aortic valve disease (DAVD), and 10 patients with congenitally bicuspid aortic valves (CBAV). For electron microscopic study, 5 cases were selected from each group. In RAVD, histological examination revealed calcification in a degenerated amorphous area at the center of fibrous thickened regions and in laminar fibrous thickened areas near the valve surface. In DAVD, calcification was observed mainly in the fibrosa near the valve ring. In CBAV, basic pathological changes were similar to those in DAVD; however, additional severe calcification of the raphe was observed, if the raphe was present. Ultrastructural examinations showed deposition of electron-dense materials in two patterns in all three groups; one pattern was observed in the interfibrillar spaces of collagen fibrils, and the other pattern was widespread macular deposition unrelated to the preexisting structure. In RAVD, microfibril-like fibrillar structures were found in the areas of deposition of electron-dense materials. These findings suggest that newly formed connective tissue degraded and became necrotic because of nutritional deprivation, especially in the thickened central area, causing calcium deposition. In DAVD and CBAV, numerous lipid vacuoles were found in the electron-dense deposition areas similar to lipid deposition in aortic atherosclerosis. Localized calcium deposition in the fibrosa suggests that the stress of valvular motion and pressure load induces sclerotic changes with the degeneration of collagen fibers, providing a core for calcification. In CBAV, the raphe was the main location of calcification, wherein spiraled collagen fibrils were observed. Increasing the hemodynamic load with abnormal structure might influence calcification. The ultrastructural pattern of calcification of the valve is common; however, additional findings suggest that the cause and mechanism are different in each type of heart valve disease.
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PMID:Comparative study of calcified changes in aortic valvular diseases. 1864 70


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