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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

D-dimer, a marker of fibrin turnover, exhibits many interesting properties as a biological marker of thrombosis. Some of the properties of D-dimer might also be used to provide additional information about patients with heart failure. In this study, we evaluate the prognostic information acquired from D-dimer concerning increased risk of cardiovascular mortality in an elderly population with symptoms associated with heart failure. A cardiologist examined 458 elderly patients, out of 548 invited, attending primary care for symptoms of dyspnoea, fatigue and/or peripheral oedema and assessed NYHA functional class and cardiac function. Abnormal systolic function was defined as EF <40% on Doppler echocardiography. Abnormal diastolic function was defined as reduced E/A ratio and/or an abnormal pattern of pulmonary venous flow. Blood samples were drawn, and BNP and D-dimer were analysed. D-dimer was analysed using an automated micro-latex assay. A statistical analysis was performed to identify the prognostic value of increased plasma concentration of D-dimer. Results showed that during a median follow-up period of 5.5 years, 68 (14%) patients died of cardiovascular disease. No gender difference was noted. A plasma concentration of D-dimer >0.25mg/L increased the risk almost 4-fold. In conclusion, D-dimer is an independent risk factor for cardiovascular mortality that may be used to risk-stratify patients with heart failure.
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PMID:Elevated D-dimer level is an independent risk factor for cardiovascular death in out-patients with symptoms compatible with heart failure. 1558 30

Reports of fatigue preceding cardiac events have recently been confirmed by large prospective studies. To assess for genetic confounding, we investigated prolonged fatigue and cardiovascular disease (CVD) in a cohort of World War II veteran twins. We examined data from a questionnaire mailed to members of the National Academy of Sciences-National Research Council (NAS-NRC) World War II Twins Registry in 1998 and 1999 which included questions on demographics, medical conditions and symptoms of fatigue. Data from twins discordant for prolonged fatigue lasting a month or more were analyzed using conditional logistic regression. Among 1955 twin pairs, 157 monozygotic and 174 dizygotic pairs (mean age 74 years) were discordant for prolonged fatigue. An association was found between prolonged fatigue and a history of myocardial infarction or coronary artery surgery adjusting for age, socioeconomic status, smoking, alcohol use and depression (OR [Odds Ratio]: 2.2; 95% CI: 1.3-4.0). When analyses were performed separately by zygosity, the association was slightly larger for monozygotic (OR: 3.3; 95% CI: 1.2-9.1) than dizygotic twins (OR: 1.9; 95% CI: 0.9-4.0). These data corroborate the association of fatigue with CVD and suggest that it is not influenced by a common genetic factor. Further studies are needed to clarify the relationship and to better understand the biologic mechanisms.
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PMID:The association between prolonged fatigue and cardiovascular disease in World War II veteran twins. 1560 7

The most important step in calcium homeostasis is the regulation of parathyroid hormone (PTH) secretion. The discovery and characterization of the calcium sensing receptor (CaR) of the parathyroid cell has led to a better understanding not only of the physiology of the parathyroid glands, but also of the development of hyperparathyroidism. Drugs acting on CaR can now be designed to treat hyperparathyroidism and osteoporosis. The workshop on primary hyperparathyroidism held at the National Institutes of Health in 2002 has recommended new guidelines for the treatment of asymptomatic hyperparathyroidism. Controversy still exists regarding the treatment of patients with non-classical symptoms, such as weakness, fatigue and depression. Primary hyperparathyroidism as a risk factor for cardiovascular disease and mortality is also debated. Improved techniques for the preoperative localization of pathological parathyroid glands have led to a shift in surgical strategy: surgeons abandon the traditional bilateral neck exploration in favor of a more limited approach. This change of strategy has not been based on the results of prospective randomized studies and the long term results are not known.
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PMID:Primary hyperparathyroidism. Update on pathophysiology, clinical presentation and surgical treatment. 1565 69

The autonomic effects of modafinil (Provigil), a psychostimulant widely used to attenuate fatigue and promote wakefulness, are currently unexplored. We assessed the effect of modafinil on autonomic nervous system. We compared oral modafinil (400 mgx1) versus placebo in 12 healthy hospitalized normal subjects in a randomized double-blind, placebo-controlled cross-over study for 3 days each with subjects in 150 mEq sodium, 70 mEq potassium balance at the Vanderbilt General Clinical Research Center. Modafinil increased resting heart rate (9.2+/-2.0 bpm; mean [+/-SE]; 95% confidence interval [CI], 4.7 to 13.6; P=0.001), resting systolic blood pressure (7.3+/-3.2 mm Hg; 95% CI, 0.2 to 14.4; P=0.044), and resting diastolic blood pressure (5.3+/-1.7 mm Hg; 95% CI, 1.4 to 9.1 mm Hg; P<0.012). Modafinil elicited a 42% higher orthostatic increase in plasma norepinephrine (0.8+/-0.3 nmol/L; 95% CI, 0.2 to 1.3; P=0.01), and caused a 33% increase in urine norepinephrine (5.1+/-1.1 nmol/L creatinine per day; 95% CI, 2.7 to 7.4, P=0.001), and an 81% increase in urine epinephrine (1.3+/-0.2 nmol/L creatinine per day; 95% CI, 1 to 2; P<0.001). The peroneal microneurographic sympathetic activity was attenuated by modafinil during orthostatic tilt (P<0.001). alpha1-Adrenoreceptor function was maintained. Modafinil substantially perturbs autonomic cardiovascular regulation by increase in heart rate and blood pressure. Autonomic changes of this magnitude encourage caution in use of modafinil in patients with cardiovascular disease.
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PMID:Modafinil elicits sympathomedullary activation. 1575 35

Dehydroepiandrosterone (DHEA) therapy is controversial due to sensationalized reports of epidemiologic studies and the over-the-counter availability of DHEA. Human clinical trials have investigated the potential efficacy of DHEA therapy in multiple conditions with resultant inconsistencies in findings. DHEA is unique compared with other adrenal steroids because of the fluctuation in serum levels found from birth into advancing age. The lower endogenous levels of DHEA and DHEA sulfate found in advancing age have been correlated with a myriad of health conditions. Also, some studies suggest gender-specific actions of endogenous and exogenous DHEA. We reviewed only pharmacokinetic studies and human clinical trials investigating the efficacy of DHEA therapy that were placebo-controlled as these provided the most reliable scientific basis for the evaluation of DHEA therapy. Pharmacodynamic studies suggest that doses of 30-50mg of oral DHEA may produce physiologic androgen levels, especially in women. These studies report a dose-dependent effect and lack of accumulation of serum androgen levels. Pharmacologic studies also reveal a gender-specific response to DHEA therapy such that testosterone levels are increased in women but not in men. Clinical trials suggest that 50mg of oral DHEA, but not <30mg, can increase serum androgen levels to within the physiologic range for young adults with primary and secondary adrenal insufficiency, possibly improve sexual function, improve mood and self-esteem, and decrease fatigue/exhaustion. Whereas DHEA replacement therapy may be effective in treating patients with adrenal insufficiency, human clinical trials investigating its efficacy in conditions such as systemic lupus erythematosus, HIV, Alzheimer disease, advancing age, male sexual dysfunction, perimenopausal symptoms, depression, and cardiovascular disease have not provided consistent findings.
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PMID:The use of dehydroepiandrosterone therapy in clinical practice. 1578 47

Cardiovascular disease represents the main cause of death among adults in the Caribbean. Primary and secondary care facilities are efficiently managed. Cardiac surgical and interventional facilities, however, exist only in a small number of territories and are mainly privately funded and are only accessible to few patients. Patients with end-stage heart failure (ESHF) are given few options apart from palliative care or to seek treatment outside of the region. Transplantation remains the 'gold standard' therapy for ESHF. Establishing a Caribbean cardiac transplantation programme would require legislative and infrastructure changes. Tissue rejection poses a problem and expensive immunosuppressants are needed. Mechanical assist devices are costly and associated with complications such as haemorrhage, thrombosis and infections. Both forms of therapy require significant technical and financial investment and do not appear to be economically viable for the Caribbean. The use of the patient's own skeletal muscle to perform biological cardiac assistance is potentially the ideal alternative. The skeletal muscle is conditioned by electrical stimulation to become fatigue resistant. It is then transposed and harnessed as an auxilliary circulatory pump. The required muscle stimulators are relatively inexpensive and the surgical techniques and postoperative care are not overly demanding. We discuss the financial and research implications of treating patients from the Caribbean who have end-stage heart failure.
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PMID:Use what you have--biological assistance for the treatment of heart failure in the Caribbean. 1589 93

As digital imaging and computing power increasingly develop, so too does the potential to use these technologies in ophthalmology. Image processing, analysis and computer vision techniques are increasing in prominence in all fields of medical science, and are especially pertinent to modern ophthalmology, as it is heavily dependent on visually oriented signs. The retinal microvasculature is unique in that it is the only part of the human circulation that can be directly visualised non-invasively in vivo, readily photographed and subject to digital image analysis. Exciting developments in image processing relevant to ophthalmology over the past 15 years includes the progress being made towards developing automated diagnostic systems for conditions, such as diabetic retinopathy, age-related macular degeneration and retinopathy of prematurity. These diagnostic systems offer the potential to be used in large-scale screening programs, with the potential for significant resource savings, as well as being free from observer bias and fatigue. In addition, quantitative measurements of retinal vascular topography using digital image analysis from retinal photography have been used as research tools to better understand the relationship between the retinal microvasculature and cardiovascular disease. Furthermore, advances in electronic media transmission increase the relevance of using image processing in 'teleophthalmology' as an aid in clinical decision-making, with particular relevance to large rural-based communities. In this review, we outline the principles upon which retinal digital image analysis is based. We discuss current techniques used to automatically detect landmark features of the fundus, such as the optic disc, fovea and blood vessels. We review the use of image analysis in the automated diagnosis of pathology (with particular reference to diabetic retinopathy). We also review its role in defining and performing quantitative measurements of vascular topography, how these entities are based on 'optimisation' principles and how they have helped to describe the relationship between systemic cardiovascular disease and retinal vascular changes. We also review the potential future use of fundal image analysis in telemedicine.
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PMID:Retinal image analysis: concepts, applications and potential. 1615 79

Erythropoietin is a hypoxia-induced hormone that is a major regulator of normal erythropoiesis. Over the last decade, the production of recombinant human erythropoietin has revolutionized the treatment of anemia associated with chronic renal failure, and has led to a greater understanding of anemia pathophysiology and to the elucidation of the interactions of erythropoietin, iron, and erythropoiesis. Anemia has been shown to be independently associated with increased mortality and disease progression. Potential survival benefits associated with correction of anemia have expanded considerably the indications of erythropoietin use in various patient populations and are leading to consideration of earlier, more aggressive treatment of mild to moderate anemia. The results of such treatment are promising in a variety of new clinical settings, including anemia associated with congestive heart failure. Furthermore, the erythropoietin receptor is widely distributed in the cardiovascular system, including endothelial cells, smooth muscle cells and cardiomyocytes and preclinical studies have established erythropoietin to be a pleiotropic cytokine with anti-apoptotic activity and tissue-protective actions in the cardiovascular system, beyond correction of hemoglobin levels. Despite some potential adverse effects, such as hypertension, and the occurrence of erythropoietin resistance, early studies in heart failure patients with anemia suggest that erythropoietin therapy is safe and effective in reducing left ventricular hypertrophy, enhancing exercise performance and increasing ejection fraction. Anemia is found in about one-third of all cases of congestive heart failure (CHF). The most likely common cause is chronic renal insufficiency, which is present in about half of all CHF cases. However, anemia can occur in CHF without renal insufficiency and is likely to be due to excessive cytokine production. The anemia itself can worsen cardiac function, both because it causes cardiac stress through tachycardia and increased stroke volume, and because it can cause a reduced renal blood flow and fluid retention, adding further stress to the heart. Long-standing anemia of any cause can cause left ventricular hypertrophy, which can lead to cardiac cell death through apoptosis and worsen CHF. Therefore, a vicious circle, cardio-renal anemia syndrome, is set up wherein CHF causes anemia, and the anemia causes more CHF and both damage the kidneys worsening the anemia and the CHF further and increasing mortality. There is now evidence that early correction of the CHF anemia with subcutaneous erythropoietin and intravenous iron improves shortness of breath and fatigue, cardiac function, renal function and exercise capacity, reducing the need for hospitalization and improving quality of life. In the present review we discuss the data on current clinical use of erythropoietin in cardiovascular disease, with the main focus on the treatment of congestive heart failure, and summarize the advances and progress made in the understanding of the hematopoietic and pleiotropic effects of erythropoietin in the cardiovascular system.
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PMID:Erythropoietin in heart failure and other cardiovascular diseases: hematopoietic and pleiotropic effects. 1624 29

L-Carnitine (L-beta-hydroxy-gamma-N,N,N-trimethylaminobutyric acid) plays an essential role in fatty acid transport in the mitochondrion. Conditions that appear to benefit from exogenous supplementation of L-carnitine include anorexia, chronic fatigue, cardiovascular disease, hypoglycemia, male infertility, muscular myopathies, renal failure and dialysis. D-Carnitine is not biologically active and might interfere with the proper utilization of the L isomer, and so there are claims that the racemic mixture (DL-carnitine) should be avoided. Despite the fact that it is known about the systemic manifestations of oral intake of this compound, oral supplementation with DL-carnitine for treatment of primary and secondary carnitine deficiency syndromes has been used in Russia for 25 years. The purpose of the present review was to contrast the differences in pharmacokinetics, phannacodynamics, biochemistry, and toxicity between treatments of L- and DL-carnitine. There is some evidence that L-carnitine and D-carnitine compete for uptake in small intestine and tubular re-absorption in kidneys. After intestinal absorption, L- and D-carnitine is transferred to organs whose metabolism is dependent on fatty acid oxidation, such as heart and skeletal muscle, and D-carnitine competitively depletes muscle level of L-carnitine. Whereas L-carnitine is found to be essential for the oxidation of fatty acids, D-carnitine causes a depletion of L-carnitine, and hindered fatty acid oxidation and energy formation. Pharmacological effects of carnitine are stereospecific, since L-carnitine was effective in various animals and clinical studies, while D- and DL-carnitine was found to be ineffective or toxic, for example, to muscle cells and to the myocardium. DL-Carnitine causes symptoms of myasthenia and cardiac arrhythmias, which disappeared after L-carnitine administration. Clinically toxic effect of D-carnitine was described in patients with renal failure on long-term haemodialysis, in adriamycin (doxorubicin) cardiotoxicity and in stable angina pectoris.
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PMID:[Stereopharmacology of carnitine]. 1649 28

Rosiglitazone is a peroxisome proliferator active receptor. gamma agonist, which increases insulin sensitivity in adipose tissue, muscle, and liver. Rosiglitazone is a member of the thiazolidinedione group, and because of its significantly positive effect on glycemic control, it is especially preferred in type 2 diabetic patients with a high cardiovascular disease risk. This drug, because of its decreasing effect on insulin resistance, is used alone or combined with type 2 diabetic drugs. A 73-year-old female patient was admitted to the emergency department with dyspnea, pink frothing phlegm, cyanosis, and tiredness. She was lethargic, uncooperative, and had no orientation. In arterial blood gases, hypoxemia and hypercapnia were found. She was taken to the general intensive care unit, and oxygen was applied via mask. The patient had a history of 10 years of diabetes mellitus, hypertension, and atherosclerotic cardiac disease, and she was using rosiglitazone for the past 6 weeks. Her chest x-ray was taken, and acute pulmonary edema was diagnosed. In her last echocardiography, which was performed 1 year before, no signs indicating cardiac failure and pleural effusion could be found. Therefore, it was concluded that pulmonary edema occurred as a complication of rosiglitazone use. After stabilizing the patient's vital signs, blood glucose levels, and lactate levels, medical treatment of diabetes mellitus was rearranged, and she was discharged on the seventh day after her admittance. In a patient with diabetes mellitus who has been admitted to the intensive care unit because of acute pulmonary edema, for differential diagnosis, use of rosiglitazone should be kept in mind during the determination of treatment. Therefore, the authors aim to discuss the effect of rosiglitazone on creating acute pulmonary edema with a case report presentation.
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PMID:Acute pulmonary edema due to rosiglitazone use in a patient with diabetes mellitus. 1669 44


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