Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seventy-three patients with an angiographically identified asymptomatic stenosis (greater than 50%) and/or ulceration of the common carotid bifurcation have been followed from 6 months to 10 years (average 4 years). All patients had previously undergone contralateral carotid endarterectomy for a transient ischemic attack (TIA) or minor stroke in that carotid territory. During follow-up, 22 patients (30%) developed new symptoms of cerebral ischemia. Twelve developed ischemia referable to the previously asymptomatic side (10 TIA's, 2 strokes). Six developed recurrent ischemic symptoms in the territory of the previously symptomatic and operated carotid artery (2 TIA's, 4 strokes). Five developed ischemia in the vertebro-basilar territory (2 TIA's, 3 strokes). Thirteen patients (17%) died during follow-up, including 6 from cardiovascular disease and 3 from stroke. In our series the incidence of stroke in the territory of a significant asymptomatic carotid plaque was low (3%). Patients were as likely to develop stroke in the territory of a previously operated carotid artery (5%) with asymptomatic carotid lesions is to keep them under review and to consider endarterectomy only if appropriate ischemic symptoms (which are most likely to be TIA's) develop.
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PMID:The natural history of asymptomatic carotid bifurcation plaques. 710 45

Some of the evidence linking a high normal haematocrit with increased risk of cardiovascular disease has been reviewed and studies have been described which show that lowering the haematocrit, even if it is in the normal range initially, may be of clinical benefit. Haemodilution in no way treats the primary cause of ischemia, but it may compensate in some measure for narrowing of the vessels.
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PMID:Is haemodilution a good thing? 718 7

The blood flow within the walls of the digestive tract must be sufficient to maintain its structural and functional integrity. All episodes of vascular insufficiency cause ischemic damage to the organ and carry the threat of diffuse or focal necrosis. Certain forms of ischemic colitis or proctitis arise from episodes of reduced peripheric or splanchnic blood flow; indeed, those which do not culminate in necrosis of the colonic wall are more frequently caused by hemodynamic disorders than by vascular occlusions. The crisis is often mitigated by the development of collateral circulation; this is, however, of rather poor quality so patients become very vulnerable to subsequent slight changes in cardiac output. Necrotic, gangrenous ischemic colitis arises from a combination of occlusive damage to the arteries and general hemodynamic disturbances. The vascular insufficiency may be slight or severe, temporary or long-lasting, localized or diffuse. In addition, the attack occurs in a septic medium in the presence of abundant microbial flora which may be highly pathologic. Thus infection complicates and aggravates the ischemic damage, resulting in the gangrenous aspect of the lesion tending to hide its ischemic origin. Indeed, the variability of the manifestations of the disease in one of its primary characteristics, and is a function of the different causative factors. A knowledge of the anatomy and pathophysiology of the splanchnic circulation and its hemodynamics is essential for a full appreciation of the diagnosis and treatment of the disorders, and for the adoption of the aggressive approach necessary to improve the poor prognosis of ischemic diseases of the colon and rectum. All treatment should be based on 1) constant, prolonged intensive care; 2) precise monitoring of any change in status; 3) rapid excision of any necrotic (often gangrenous) tissue. Ischemic colitis is most likely to occur in elderly patients with a history of cardiovascular disease, but can also affect younger individuals. It is a frequent, potentially lethal, entity. Although it can be classified as a separate disease on the basis of its clinical, radiological and anatomical characteristics, it is often confused with other disorders of the colon. Although the abdominal surgeon is most likely to be concerned with this disease, the vascular surgeon incising the lower aorta should always be on the look-out for segmentary ischemia of the distal colon which may occur following operation.
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PMID:Ischemic diseases of the large intestine. 727 5

The heart is the most susceptible of all the organs to premature aging and free radical oxidative stress. Clinical research has clearly documented the role of free radical damage and the progression of numerous degenerative diseases, particularly cardiovascular disease. This may be the result of acute ischemia-reperfusion injury, endothelial damage of hyperhomocysteinemia, as well as chronic oxidative damage secondary to lipid peroxidation. Fortunately, although highly responsive, and therefore vulnerable to the effects of oxidative stress, the heart is also receptive to the benefits of targeted phytonutrients, antioxidants, and nutritionals. The effects of antioxidant nutrients have been extensively evaluated in epidemiological, population, and clinical studies. Phytonutrients such as the natural flavonoids and carotenoids found in fresh fruits and vegetables or vitamins C, E, and beta-carotene have powerful antioxidant effects. In addition, minerals like selenium and nutrients such as coenzyme Q10 will minimize free radical risk and optimize a favorable outcome from the ubiquitous presence of oxidative stress on the cardiovascular system. The B complex, particularly folic acid, B12, and B6 are also essential in the prevention of hyperhomocysteinemia, another major risk factor for the circulatory system. Measures to minimize accumulation of heavy metals in the body, especially iron and copper, which are capable of initiating adverse free radical reactions, will also help to assuage oxidative stress. Thus, the combination of a healthy diet supplemented with antioxidants and phytonutrients may be useful in the prevention and promotion of optimum cardiovascular health.
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PMID:Free radicals, oxidative stress, oxidized low density lipoprotein (LDL), and the heart: antioxidants and other strategies to limit cardiovascular damage. 758 73

Several patients with chronic critical limb ischemia show angiographically an isolated popliteal segment (IPS) and a single calf vessel (SCV) with no direct communication to the former. In this situation a bypass can be inserted from the common femoral artery to the IPS or to the SCV. The results of 73 bypass procedures--40 to an isolated popliteal segment and 33 to a single calf vessel for limb salvage--were prospectively evaluated. Eighty percent of the grafts were performed with an autogenous saphenous vein (ASV), the rest with a thin wall polytetrafluoroethylene (PTFE) prosthesis. The mean age of our patients was 75 years and many suffered from cardiovascular disease. The operative mortality rate was 3% and the mean postoperative survival 32 months. Three year patency and limb salvage rates for ASV grafts was 83% and 87% (IPS) respectively 77% and 76% (MCV); for PTFE grafts 58% and 88% (IPS) respectively 17% and 50% (MCV). There was no significant difference found in patency and limb salvage rates of the two procedures if the graft was an autogenous saphenous vein (p > 0.05). The PTFE prosthesis was only suitable for grafts inserted to the isolated popliteal segment.
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PMID:[Chronic critical leg ischemia: revascularization of the isolated popliteal segment in comparison with femoro-distal bypass]. 772 79

Diabetes mellitus is now the most common cause of end-stage renal disease (ESRD) in the U.S., and the percentage of ESRD patients with diabetes is increasing yearly. One-year survival in such patients is poorer than in those with other etiologies of ESRD but has improved from 64% to 74% over the past decade. However, overall 5-year survival on dialysis is still less than 20% in this population. It is controversial whether hemodialysis or peritoneal dialysis (CAPD, CCPD) is the best choice. Advantages of hemodialysis include its ready availability and convenience for patients, who are frequently incapacitated by blindness, cerebrovascular disease, and/or amputations. However, patients may tolerate dialytic ultrafiltration poorly due to autonomic neuropathy. Maintenance of vascular access is difficult, which may contribute to inadequate dialysis in some patients. Cardiovascular disease remains the most common cause of death. Management of coronary artery disease is difficult because of the high prevalence of silent ischemia. Control of blood pressure is of paramount importance in preventing cardiovascular complications. Improved survival in diabetics who were dialyzed in a more intensive than usual fashion has been reported recently. In addition, much of the difference in survival rates between diabetics and nondiabetics can be accounted for by the poorer nutritional status in the former group. Thus attention to the dose of dialysis administered and assurance of adequate nutrition should result in improved survival of the diabetic patient on hemodialysis.
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PMID:Hemodialysis in the diabetic patient with end-stage renal disease. 785 13

CDP-choline, supplied exogenously as citicoline, has beneficial physiological actions on cellular function that have been extensively studied and characterized in numerous model systems. As the product of the rate-limiting step in the synthesis of phosphatidylcholine from choline, CDP-choline and its hydrolysis products (cytidine and choline) play important roles in generation of phospholipids involved in membrane formation and repair. They also contribute to such critical metabolic functions as formation of nucleic acids, proteins, and acetylcholine. Orally-administered citicoline is hydrolyzed in the intestine, absorbed rapidly as choline and cytidine, resynthesized in liver and other tissues, and subsequently mobilized in CDP-choline synthetic pathways. Citicoline is efficiently utilized in brain cells for membrane lipid synthesis where it not only increases phospholipid synthesis but also inhibits phospholipid degradation. Exogenously administered citicoline prevents, reduces, or reverses effects of ischemia and/or hypoxia in most animal and cellular models studied, and acts in head trauma models to decrease and limit nerve cell membrane damage, restore intracellular regulatory enzyme sensitivity and function, and limit edema. Thus, considerable accumulated evidence supports use of citicoline to enhance membrane maintenance, membrane repair, and neuronal function in conditions such as ischemic and traumatic injuries. Beneficial effects of exogenous citicoline also have been postulated and/or reported in experimental models for dyskinesia, Parkinson's disease, cardiovascular disease, aging, Alzheimer's disease, learning and memory, and cholinergic stimulation.
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PMID:Metabolism and actions of CDP-choline as an endogenous compound and administered exogenously as citicoline. 786 46

Previous invasive studies have suggested that coronary flow reserve is impaired in patients with left ventricular hypertrophy (LVH) and symptoms of ischemia. We tested whether transesophageal Doppler, a semiinvasive technique, can detect altered characteristics of baseline coronary blood flow velocity in such patients. Thirty patients with LVH (hypertrophic cardiomyopathy in 4, aortic stenosis in 17, hypertension in 9) were studied. Fourteen patients had asymptomatic LVH. Sixteen patients had clinical symptoms of ischemia with angiographically normal epicardial coronary arteries. Ten subjects with no cardiovascular disease were studied as a control group. Peak diastolic and systolic coronary flow velocities were recorded in the proximal part of the left anterior descending artery (LAD) with the use of pulsed Doppler guided by color flow imaging. Patients with symptomatic LVH had higher diastolic peak coronary flow velocity (81 +/- 10 cm/sec, p = 0.0001) compared with normal subjects (41 +/- 8 cm/sec) and patients with asymptomatic LVH (44 +/- 8 cm/sec). In patients with asymptomatic LVH the diastolic coronary flow velocity/indexed ventricular mass ratio was lower (0.28 +/- 0.09 cm/gm/m2, p = 0.0001) compared with symptomatic patients (0.52 +/- 0.12 cm/gm/m2) and compared with controls (0.47 +/- 0.16 cm/gm/m2). Patients with symptomatic LVH but no aortic stenosis also had higher peak systolic coronary flow velocity (38 +/- 9 cm/sec) compared with the other groups (p = 0.0001). In the group of patients with aortic stenosis a significant inverse linear relation was found between peak systolic coronary flow velocity and peak pressure gradient (r = -0.60, p 0.01). In conclusion, patients with symptomatic LVH have abnormally high baseline coronary flow velocities resulting in magnified intimal shear stress. Because flow velocity equals flow/vessel cross-sectional area, it is suggested that high coronary flow velocities in patients with symptomatic LVH result from both augmented coronary flow and failure of the vessel to enlarge commensurately with the increase in LV mass (relative functional stenosis). In patients with aortic stenosis, peak systolic coronary flow velocity appears to be influenced by transvalvular pressure drop.
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PMID:Abnormal coronary flow velocity pattern in patients with left ventricular hypertrophy, angina pectoris, and normal coronary arteries: a transesophageal Doppler echocardiographic study. 807 11

The development and validation of quantitative assay techniques for the noninvasive study of human myocardium has opened up new avenues for the study of the normal and diseased human heart's physiology. Measurements of regional myocardial blood flow, which delineates nutrient rather than coronary blood flow, has enabled the exploration of the coronary microcirculatory physiology under normal and abnormal conditions. It permits the study of pharmacologic effects and of cardiovascular disease on the coronary resistance and capillary perfusion. If combined with metabolic assay techniques, the transcapillary exchange of substrates in oxygen can be quantified and changes imposed by physiologic interventions and substrate metabolism being measured. These study approaches further serve to characterize changes in response to reductions in coronary blood flow as well as altered states of potentially reversible contractile function. It is anticipated that further studies with PET will clarify at the microcirculatory level the changes associated with ischemia, post-ischemic stunning and myocardial hibernation. Further, it offers the possibility to measure potentially beneficial effects of therapeutic interventions or, alternatively, to provide a rationale for novel therapeutic approaches.
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PMID:Cardiac PET: microcirculation and substrate transport in normal and diseased human myocardium. 807 62

The incidence of coronary heart disease and myocardial infarction fell gradually during the seventies. Reasons for this decline are not well understood. Speculations include changes of life style and health care. However, cardiovascular disease is still the leader of mortality in Western developed countries. Mortality of myocardial infarction has also declined. The major benefit was associated with broad establishment of coronary care units, smaller steps were achieved by various progresses in medical treatment. In contrast, the incidence of heart failure has increased. The major etiology of heart failure nowadays is coronary heart disease, especially large or recurrent myocardial infarction. The incidence of heart failure in patients having recovered from myocardial infarction is dramatically higher than in normal population. The Framingham Study showed an incidence of 14% in five years following a myocardial infarction. Prognosis of patients with manifestation of symptoms of heart failure is very poor. Patients with heart failure had an overall six years mortality of 55%. These observations suggest that coronary care units, thrombolysis and modern treatment as developed so far, suppressed in-hospital mortality and improved survival for the first year after a myocardial infarction. Thus, patients with larger infarcts who had succumbed early under previous regimens, survived. They carry, however, the burden of severely impaired left ventricular function, high probability to develop heart failure, and of a dubious long-term prognosis. Large efforts have put upon development of scores to estimate long-term prognosis after a myocardial infarction. With the development of techniques, composition of scores changed. However, residual ischemia, major left ventricular dysfunction, and ventricular arrhythmias are the basis of most scores indicating an adverse prognosis after an infarction. This review will be limited to the prognostic impact of left ventricular dysfunction and development of heart failure post myocardial infarction. A hypothetic cascade of events which may lead from myocardial infarction to heart failure and death is schematically outlined in Figure 1. Loss of contractile myocardium results in left ventricular dysfunction which may induce dilatation of the left ventricle, heart failure and ultimately death. This paper focuses on the evidence for the prognostic impact of the single steps and the whole cascade. Figure 1 shows in parenthesis the variables which were frequently measured to assess loss of contractile tissue, left ventricular dysfunction, and dilatation. Since heart failure is understood as a clinical syndrome of symptoms, it may only be semi-quantitated according to the classification of the New York Heart Association (NYHA).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Epidemiology and prognosis of myocardial infarct and chronic heart failure]. 812 20


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