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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Conventional risk factors predict only about 30-50% of incidental cases in cardiovascular diseases, which are still the leading cause of death in western societies. During the last decade, the importance of thrombosis as an essential mechanism in acute myocardial infarction (AMI) and stroke has been established. The introduction of thrombolysis has led to an impressive reduction in AMI case fatality and possibly also to a substantial amelioration of its prognosis. Evidence from experimental, clinical and epidemiological studies suggest, that several hemostatic and hemorheological factors (e.g., fibrinogen, Factor VII, plasma viscosity, hematocrit, red blood cell aggregation, total white cell count) might not only play an important role in the evolution of acute thrombotic events, but may also take part in the pathophysiology of atherosclerosis. An increasing number of studies reports altered hemostatic and hemorheological parameters to be associated with smoking, hyperlipoproteinemia, and high blood pressure, as well as with adverse dietary habits and other life-style factors. To date, their way of interaction with the atherosclerotic process is poorly understood. Hemorheological or hemostatic mechanisms that might promote thromboatherogenesis include the predisposition to thrombosis via a hypercoagulable state, the enhancement of atherosclerosis by fibrinogen and its metabolites, and finally the reduction of blood flow through various rheological effects (e.g., increase in plasma viscosity and red cell aggregation, or leukocyte activation). Future research should focus in more detail on the interrelationship between accepted risk factors and the hemostatic system as well as hemorheological parameters. Deeper insight into the mechanisms involved might lead to new preventive strategies as well as to therapeutic procedures in the management of atherosclerosis and associated thrombotic events.
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PMID:The possible role of hemorheology in atherothrombogenesis. 163 76

The hypothesis that blood rheology is of prognostic value in patients with arteriosclerotic diseases was tested in a prospective study of 843 patients at a rehabilitation clinic. They were tested for blood serum and plasma viscosity, hematocrit, fibrinogen, red cell aggregation and deformability, erythrocyte sedimentation rate, white cell count, cholesterol, and triglycerides. End points were defined as a second stroke or myocardial infarction or cardiovascular death within two years of the initial examination. Patients suffering such end points as compared with matched pairs (n = 74; matching criteria: identical manifestation of arteriosclerosis, identical sex and similar age and risk factors) had significantly higher native blood viscosity (p = 0.002), red cell aggregation (p = 0.01), serum viscosity (p = 0.01), fibrinogen (p = 0.02), and cholesterol (p = 0.01). It is concluded that rheologic factors are associated with the prognosis in patients with arteriosclerotic diseases.
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PMID:Can rheologic variables be of prognostic relevance in arteriosclerotic diseases? 176 30

A prospective study of 1969 patients with intermittent claudication receiving placebo medication for a minimum of 1 year is reported. Patients were carefully monitored and only four patients were lost to follow-up. Annual mortality was 4.3%. Thirty-six patients developed a definite myocardial infarction, 27 a major stroke, 32 required a major amputation and 111 required surgical or radiological intervention for deteriorating ischaemia of the leg. The entry characteristics of the patients were analysed as a predictor of serious cardiovascular events. The most sensitive predictors of total mortality were age, history of coronary heart disease and an ankle/arm pressure ratio below 0.5. Of the laboratory measurements performed only the initial white cell count was a significant predictor of myocardial infarction, stroke and vascular deaths.
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PMID:The fate of the claudicant--a prospective study of 1969 claudicants. 2185 19

The hypothesis that blood rheology is of prognostic value in stroke patients was tested in a prospective study. A total of 523 patients in the rehabilitation phase of stroke (outside the acute phase reaction after stroke) were tested for blood, serum and plasma viscosity, haematocrit, fibrinogen, red cell aggregation and deformability, ESR, white cell count, cholesterol and triglycerides. Endpoints were defined as a second stroke (lethal or not) within 2 years after the initial examination. Patients suffering such endpoints exhibit elevated blood viscosity, red cell aggregation, plasma and serum viscosity, fibrinogen and cholesterol levels, compared to patients without endpoints. It is concluded that rheological factors are associated with the prognosis after a first stroke.
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PMID:Impaired blood rheology: a risk factor after stroke? 204 Aug 72

Hematocrit, total white cell and platelet counts, plasma urea and creatinine concentrations were estimated in 291 patients (mean age 70 +/- 12 years) admitted consecutively over a 6-month period to a district general hospital with acute stroke. Urinary albumin/creatinine ratio was also determined in a subgroup of patients during a follow-up visit 3 months after ictus. Results were compared with those from age- and sex-matched community controls. Total white cell count was elevated in all types of stroke compared with values from control subjects. Platelet count, plasma urea and creatinine concentrations were higher and the plasma albumin/globulin ratio was lower among patients with ischemic stroke. Elevated total white cell count, urea and creatinine, which were of prognostic significance, were found to be associated with the severity of stroke as indicated by the Glasgow coma score, and did not have any independent prognostic value. Elevated hematocrit was not shown to be a risk factor and did not have any prognostic significance. A low plasma albumin/globulin ratio, an index of plasma viscosity, was a possible risk factor for ischemic strokes. Urinary albumin/creatinine ratios in the highest quintile increased the risk of stroke 13-fold.
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PMID:A case control study of some hematological and biochemical variables in acute stroke and their prognostic value. 209 14

One hundred and twenty-two consecutive patients admitted with acute stroke in a carotid distribution had venous blood taken for haematocrit (Hct), haemoglobin (Hb), white cell count (WCC) and urea estimations. Patients were followed for 12 weeks to determine the influence of haematocrit upon fatality. There were 96 patients aged greater than or equal to 65 years and 26 patients less than 65 years. No association could be demonstrated between Hct levels and fatality at 4 or 12 weeks. Regression analysis demonstrated that only increasing age (P less than 0.05) and a raised WCC (P less than 0.005) were independent factors significantly associated with fatality at both 4 and 12 weeks. In the elderly stroke patient (greater than or equal to 65 years) only WCC was significantly associated with fatality (P less than 0.005). Haematocrit levels are of no prognostic value for fatality in acute stroke. A raised white cell count is an important and independent prognostic factor for fatality at both 4 and 12 weeks following stroke.
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PMID:The prognostic value of haematocrit in acute stroke. 323

Traditionally, blood rheology tests have been used in diagnosis and monitoring of infection, rheumatic diseases and malignancy, and are still of clinical value in these conditions. In the last twenty years, clinical and epidemiological studies have shown that the haematological determinants of blood flow resistance (haematocrit, fibrinogen, white cell count and altered red and white cell rigidity) are also associated with nutritional, metabolic, endocrine and vascular disorders. Decreased red cell deformability may contribute to reduced red cell survival and anaemia in burns, malaria, liver disease and kidney failure. In trauma and inflammatory disease, overt hyperviscosity is usually prevented by vasodilatation and reduction in the haematocrit. However, low-flow states may arise systemically from haemoconcentration (contracted plasma volume, Chapter 3) in severe burns, inappropriate red cell transfusion, or dehydration due to illness; systemically in circulatory shock; and locally in venous thrombosis or arterial disease. In such circumstances, the intrinsic flow resistance of blood may perpetuate flow disturbance, ischaemia and thrombosis. Conversely, optimal levels of haematocrit, fibrinogen and white cell count may be lower than normal in low-flow states. Haemodilution by colloid infusion is beneficial in burns, shock, major surgery, prevention of postoperative venous thrombosis, chronic stable claudication and possibly in acute stroke and retinal vein thrombosis. Plasma exchange may be beneficial in severe Raynaud's phenomenon. Defibrination with ancrod is effective in prevention and treatment of venous thrombosis but its role in arterial disease is unproven. The benefits of streptokinase therapy in venous thrombo-embolism and acute myocardial infarction may be partly rheological, due to fibrinogen depletion. Drugs with rheological effects may be beneficial in intermittent claudication.
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PMID:Blood rheology in general medicine and surgery. 332 67

Eighteen patients with recent ischemic stroke were compared with an equal number of matched controls. Standardized suspensions of red cells as well as of red and white cells were filtered in a new filtration apparatus capable of discriminating between cell deformability and filter occlusion. Results show that red cell deformability, although slightly lower than in controls, is not significantly altered in stroke patients. Filter occlusion, however, was significantly higher in patients when red and white cell suspensions were filtered, but not when red cell suspensions were used, suggesting that white cell filterability is impaired after stroke, which could be due to decreased deformability and/or increased adhesiveness of leukocytes. Slowed white cell passage may also occur in the living microcirculation and may present an obstacle to nutritive flow in exchange vessels, possibly contributing to local ischemia and tissue necrosis after stroke.
Stroke
PMID:Leukocyte rheology in recent stroke. 381 Jul 70

Clinical and laboratory abnormalities and the presence of atrial fibrillation on admission were examined in relation to hospital mortality in a retrospective study of the 320 patients with acute stroke admitted to a medical unit in a 5-year period. Of clinical factors, only increasing age and the presence of coma were associated with mortality. Atrial fibrillation, present in 25% of all patients, was associated with an increased mortality in patients aged 60-79 years (67% vs 44%, p less than 0.01). In patients under 75 years the mortality associated with raised haematocrit (0.50 or more), present in 11% of all patients, was more than twice as high as it was in those with lower haematocrit (71% vs 31%, p less than 0.005). Other laboratory variables associated with a high mortality were increased levels of mean red cell volume, white cell count, erythrocyte sedimentation rate, globulin, and blood urea and creatinine; and decreased levels of albumin. The high prevalence of and increased mortality associated with atrial fibrillation and raised haematocrit in stroke patients indicate the need for further studies of stroke prevention and treatment in these patients.
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PMID:Relation of atrial fibrillation and high haematocrit to mortality in acute stroke. 613 30

An 83-year-old woman, largely bedridden since a stroke 2 years before, was hospitalized because of upper abdominal pain, nausea and obstipation. She had regularly been taking laxatives of the anthraquinone type. She had a fever of 38.6 degrees C and leukocytosis (14,900/microliters). Radiological examination revealed volvulus of the sigmoid colon with ileus. As she vehemently refused an operation, it was attempted to reduce the volvulus endoscopically. At the first coloscopy the volvulus was untwisted. At that time there were already areas of necrosis in the rectosigmoid and descending sigmoid portions. As the volvulus recurred three days later, another coloscopic derotation was performed, this time with fixation of the sigmoid by three gastrostomy tubes for 20 days. The further course was uncomplicated, the patient had regular bowel movements and became free of fever and symptoms. The white cell count returned to normal and the intestinal mucosa healed histologically without scarring. There has been no recurrence for 10 months. The conventional treatment of volvulus of the sigmoid is decompression followed by sigmoid resection. This case describes for the first time the nonoperative treatment by percutaneous endoscopic colopexy.
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PMID:[Percutaneous endoscopic colopexy--a new treatment possibility for volvulus of the sigmoid]. 771 43


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