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

The authors describe their experience with 40 patients operated upon during the last five years because of pathological processes of the large blood vessels of the neck. In seven cases pathological conditions unrelated to the systematic diseases of the arteries (birth defects, the results of injuries and tumours) existed, while the remaining 33 patients suffered from arteriosclerotic lesions most commonly located on the carotid artery. The localization of the pathological process and the number and extent of the neurological lesions are described. The authors particularly stress the importance of the period which elapses from the first signs of ischemic lesions to the moment of surgical intervention. The aim of surgical intervention is primarily to prevent ischemia and simultaneous cerebral apoplexy, and only after this to prevent the progressions of the existing ischemic changes. Patients with temporary attacks of ischemia without neurological attacks are ideal cases for surgical intervention. Good results can be achieved on patients with apoplexy within the first six hours from the moment at which the attack occurs. Intervention after a longer period gives uncertain results. Good results can be expected only when the diagnosis and localization of the vascular changes are exact and the neurological and general condition of the patient is precisely evaluated. This demands team work by the roentgenologist, the neurologist and the vascular surgeon.
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PMID:[Reconstructive surgery in diseases of the blood vessels of the neck]. 87 54

The effects of atrial pacing on tissue metabolite levels known to be sensitive to ischemia were examined. Anesthetized dogs were thoracotomized and a pacing electrode was sutured to the right atrium. Pacing at rates of 200 or 250 beats/min (10 animals per group) was performed for 15 min after base-line hemodynamic data had been obtained. At the end of the pacing period, a transmural biopsy was taken, frozen in liquid nitrogen, and sectioned into subepicardial, midmyocardial, and subendocardial layers. ATP, phosphocreatine, lactate, and glycogen were extracted and analyzed. Significant (P less than 0.001) transmural gradients of each of these metabolites existed in the control group. Pacing had no significant (P greater than 0.2) effect on any metabolite from layer to layer at 200 or 250 beats/min. However, indices of heart work (i.e., contractility (dP/dt), stroke work, and stroke volume) demonstrated significant reductions (P less than 0.01) due to pacing, while circumflex artery blood flow increased more than twofold (P less than 0.001) at the highest rate. These data suggest that physiologic autoregulation occurred during pacing and protected the subendocardium from stress-induced ischemic insult.
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PMID:Transmural metabolic gradients in the normal dog left ventricle: effect of right atrial pacing. 88 64

Recent epidemiologic studies have suggested that cardiac disease in common in diabetics and may often have a noncoronary basis. To examine the status of the left ventricle, 17 adult-onset diabetics of familial type without hypertension or obesity underwent hemodynamic study and were compared to 9 controls of similar age. Of the 17, 12 subjects had no significant occlusive lesions by coronary angiography. From this group eight without heart failure had a modest, but significant, elevation of left ventricular end-diastolic pressure. End-diastolic and stroke volumes were reduced, but ejection fraction and mean rate of fiber shortening were within normal limits. The left ventricular end-diastolic pressure/volume ratio was significantly higher than controls. Afterload increments effected a significant increase of filling pressure compared to normals without a stroke volume response, consistent with a preclinical cardiomyopathy. Four patients with prior heart failure had similar but more extensive abnormalities. None had local dyskinesia by angiography, and lactate production was not observed during pacing-induced tachycardia. Left ventricular biopsy in two patients without ventricular decompensation showed interstitial collagen deposition with relatively normal muscle cells. These findings suggest a myopathic process without ischemia. Postmortem studies were performed in 11 uncomplicated diabetics. Nine were without significant obstructive disease of the proximal coronary arteries, and the majority succumbed with cardiac failure. On left ventricular sections, none had evident luminal narrowing of the intramural vessels. All nine exhibited periodic acid-Schiff-positive material in the interstitium. Collagen accumulation was present in perivascular loci, between myofibers, or as replacement fibrosis. Multiple samples of left ventricle and septum revealed enhanced triglyceride and cholesterol concentrations, as compared to controls. Thus, a diffuse extravascular abnormality may be a basis for cardiomyopathic features in diabetes.
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PMID:Evidence for cardiomyopathy in familial diabetes mellitus. 89 79

The yield of infarcted hemispheres following unilateral carotid ligation in gerbils under ketamine anesthesia substantially exceeded that occurring under pentobarbital anesthesia. In addition to increasing the gerbil stroke model's efficiency, ketamine provided a shorter recovery period, thus allowing earlier observation of clinical signs of brain injury. These results support the contention that anesthetic agents may modify the response of central neuronal tissues to acute ischemia.
Stroke
PMID:Modification of cerebral ischemic damage by anesthetics. 90 64

In 180 patients, cerebral blood flow was measured between one and six weeks after acute cerebrovascular ischemia. Patients were grouped according to their clinical deficits at the time of blood flow study. Statistical analysis revealed highly significant differences among the flow values of the groups. The patients were followed up for a period of up to 6 years (mean, 34 months) after the attack, and then regrouped. In these groups, the statistical significances of differences among the flow values was even higher. Patients also were grouped according to changes in neurologic status, and again the flow values differed significantly among the groups. The results show significant relationships among flow values after cerebrovascular ischemia and neurologic deficits, change in status, and the final functional state. Cerebral blood flow measurement together with other clinical signs permits an estimation of a patient's chance for functional recovery after a stroke.
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PMID:Long-term prognosis in stroke related to cerebral blood flow. 91 Dec 27

Fifty patients with acute myocardial infarction were studied serially to evaluate the extent and nature of functional cardiovascular impairment and the time course of recovery. Reinfarction or death occurred in six patients. Peak workload during bicycle exercise in a subgroup of 25 patients with maximal initial test and complete follow-up increased from 334 to 409 kpm/min (P less than 0.01) bwtween three and six weeks. There was further significant (P less than 0.01) improvement between three and six months from 438 to 488 kpm/min. The incidence of ischemia at a constant workload decreased between three and six weeks without any significant changes in heart rate or blood pressure. Mean cardiac output during exercise at three months was 6.5 and at six months 7.8 L/min (P less than 0.05). Corresponding values for stroke volume were 61 and 72 ml (P less than 0.05). The data suggest that in clinically stable patients there is an early improvement of the relation between myocardial oxygen supply and demand and a late improvement of functional capacity associated with increased stroke volume and cardiac output.
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PMID:Cardiovascular function during early recovery from acute myocardial infarction. 92 62

It was established that in the acute period of the ischemic stroke in the maiority of cases a change of isoenzyme structure of LDG thrombocytes was due to a decrease of LDG3 activity. In a number of patients the dominant change in the spectrum was determined by LDG and LDG4 fractions. The changes were of a stable character up to 10 weeks. LDG4 increase was characteristic of the isoenzymes spectrum in the patients with a severe development of the disease and in the patients in the remote period of the stroke. The obtained data can serve as a criterion for evaluating the adaptive changes in acute brain ischemia.
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PMID:[Thrombocyte lactate dehydrogenase isoenzymes in patients with ischemic stroke]. 96 Dec 81

The mechanism of elevation of left ventricular end-diastolic pressure during acute global ischemia was evaluated by examiniation of the relative contributions of a decrease in contractility and an alteration of the pressure-volume relationship. The external circumference (mercury-in-silastic gauge) pressure relationship, as an index of the pressure-volume relationship, was studied in beta adrenergic and ganglionic blocked, open chest dogs on right heart bypass at constant heart rate ane aortic pressure. Ischemia of one and two hours' duration was produced by reducing total coronary blood flow in cannulated left and right coronary arteries until left ventricular end-diastolic pressure rose significantly. At a constant stroke work, left ventricular end-diastolic pressure rose from 5.0 +/- 0.5 to 15.0 +/- 0.5 cm H2O in the experiments of one hour of ischemia, and from 7.0 +/- 1.0 to 17.0 +/- 1.0 cm H2O in experiments of two hours of ischemia. Ischemia was followed by one hour of restoration of coronary blood flow. Ischemia produced a marked depression of ventricular function: stroke work, considered at a left ventricular end-diastolic pressure of 15 cm H2O, decreased from 21.0 +/- 3.0 to 3.5 +/- 0.5 gm-m, and from 15.0 +/- 2.0 to 2.5 +/- 0.5 gm-m, in the experiments of one and two hours, respectively. Neither ischemia nor reflow changed the pressure-volume relationship. Thus, the elevation of left ventricular end-diastolic pressure during ischemia in an otherwise normal canine myocardium is due to a decrease in systolic performance of the heart rather than to an alteration of the pressure-volume relationship.
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PMID:Left ventricular end-diastolic pressure volume relationships with experimental acute global ischemia. 108 86

The effect of intravenous infusion of 10 per cent glycerol on regional cerebral blood flow (using hydrogen bolus and Xenon-133 (133Xe) clearance methods) and metabolism was investigated in 57 patients with recent cerebral infarction. Hemispheric blood flow (HBF) increased, together with increase in regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV), in foci of brain ischemia. Hemispheric oxygen consumption (HMIO2) decreased together with hemispheric respiratory quotient. Systemic blood levels of glucose, lactate, pyruvate, and triglycerides also increased after glycerol while free fatty acids (FFA) and inorganic phosphate (Pi) decreased. Hemispheric glucose consumption was unaltered after glycerol so that hemispheric glucose to oxygen ratio tended to rise. Pyruvate and lactate production by brain was unchanged. Glycerol moved across the blood brain barrier into brain and cerebrospinal fluid (CSF). Release of FFA and Pi from infarcted brain was reversed by glycerol. Total phosphate balance was maintained actoss brain both before and after glycerol infusion. Triglycerides increased in CSF after glycerol, originating either from cerebral blood or as a result of lipogenesis in cerebral tissue. The EEG Recording and neurological status of the patients improved despite decreased brain oxygen consumption. Results of this study suggest that after intravenous infusion of 10 per cent glycerol in patients with recent cerebral infarction, glycerol rapidly enters the CSF and brain compartments and favorably affects the stroke process in two ways: first, by redistribution of cerebral blood flow with increase in rCBF and rCBV in ischemic brain secondary to reduction in focal cerebral edema; and second glycerol may become an alternative source of energy either by being directly metabolized by the brain, or indirectly, by enhancing lipogenesis, or by both processes. Involvement of glycerol in lipogenesis with esterification to accumulated FFA might lead to improved coupling of oxidative phosphorylation, a hypothesis that fits the finding of improved neuronal function despite further decrease in cerebral hemispheric oxygen consumption.
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PMID:Circulatory and metabolic effects of glycerol infusion in patients with recent cerebral infarction. 109 Mar 93

Echocardiography has many attributes that are desirable for diagnostic and research studies in acute myocardial infarction patients. It does not alter the physiologic state being evaluated, is relatively inexpensive, and does not interfere with other hospital procedures. For these reasons, the test may be repeated frequently and used to monitor the changes after acute infarction. Useful information about left ventricular volume, diastolic pressure, and segmental wall motion may be obtained. Because echocarciographic estimates of stroke volume, ejection fraction, and velocity of circumferential fiber shortening are based on motion seen in only one "ice-pick" view of the heart, it is likely that they will be less reliable in patients with asynergy of contraction. Although a definite diagnosis of acute myocardial infarction cannot be made by echocardiography, abnormalities of wall motion may occur very early and support a clinical impression of infarction. An echocardiogram may also reveal changes suggesting ischemia or infarction (abnormal motion) in patients who have atypical chest pain and no other objective evidence of coronary artery disease.
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PMID:Applications of echocardiography in acute myocardial infarction. 110 66


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