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

Left ventricular ejection fraction, systolic blood pressure and plasma norepinephrine were measured in six normotensive and six mildly hypertensive subjects during rest and psychological stress. Compared with rest, 8 of the 12 subjects developed significant (P less than 0.05) changes in ejection fraction (increase in 6, decrease in 2); 10 of 12 subjects developed significant elevations of plasma norepinephrine; and all developed significant increases in systolic blood pressure. When the stress effects were examined for the total group, as opposed to within subjects, there were significant increases in plasma norepinephrine (P less than 0.001) and systolic blood pressure (P less than 0.001) but, interestingly, mean ejection fraction and stroke volume remained unchanged, implying stress led to increased left ventricular contractility.
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PMID:Left ventricular performance during psychological stress. 271 99

The observation that aerobically fit persons react to physical load with a smaller sympathetic response than do less fit subjects suggests that their response to psychological stress might also be reduced. The evidence for this, however, is far from consistent. It was argued that this inconsistency might be due to the incomplete measurement of the response system involved. In the present experiment two groups, which differed strongly in maximal aerobic power, were compared with respect to their cardiovascular response to a laboratory stressor. In addition to the traditional heart rate and blood pressure measurements, pre-ejection period, cardiac output, and peripheral resistance were assessed. Since only the part of the stress response that is not accounted for by metabolic needs might have pathological significance, the so-called "additional" responses were also measured. Fitness was shown to be associated with smaller sympathetic effects on both heart and vessels. The decrement in pre-ejection period and the heart rate response were smaller in the high fit group. The total peripheral resistance and diastolic blood pressure responses pointed to a much stronger vascular reactivity in the low fit group. Unexpectedly cardiac output did not increase during stress. The strong heart rate response in the low fit group was compensated by a reduction in stroke volume, which probably originated in an increased peripheral resistance. The largest discrepancy between the effects of sympathetic activation during stress and exercise occurred in the vessels, as demonstrated by the large "additional" response in total peripheral resistance during stress. The data point to the often neglected role of vascular processes in experiments of this kind. Furthermore, it seems necessary to take the effect of fitness into account when comparing subjects with respect to their cardiovascular stress response.
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PMID:Aerobic fitness and the cardiovascular response to stress. 292 53

Cardiovascular and Renal function were examined in two populations of long-term insulin-dependent diabetics, those with microalbuminuria, a sign of early, subclinical nephropathy and those with clinically manifest diabetic nephropathy. In addition, clinical variables of possible importance for the occurrence and prognosis of diabetic nephropathy were analyzed. Microalbuminuria - a mean of three over-night urinary albumin excretion rates greater than 20 micrograms/min - was found in 16% of Albustix-negative, normotensive, insulin-dependent diabetics. The microalbuminurics had higher supine blood pressures than normoalbuminurics. The albumin excretion rate in microalbuminurics correlated to blood pressure at rest but not to glycosylated haemoglobin. The cardiovascular responses to five different test manoeuvres revealed more evident signs of autonomic nerve dysfunction in microalbuminurics than in normoalbuminurics. The circulatory reactions during mental stress however, were almost identical in the two subgroups. Despite similar glomerular filtration rate and renal plasma flow the albumin excretion during mental stress increased in microalbuminurics, but remained unchanged in normoalbuminurics. It is postulated that a disturbance of glomerular basement membrane permeability is a pre-requisite for the elevated albumin excretion seen in microalbuminurics. Inability to regulate glomerular haemodynamics, due to autonomic nerve dysfunction, may also be a contributing factor. Such dysfunction perhaps even explains why microalbuminurics have higher blood pressures at rest compared with normoalbuminurics. In manifest diabetic nephropathy the rate of renal functional decline correlated to arterial blood pressure, while glycemic control showed no such relation. Patients with rapidly progressive nephropathy showed higher values of growth hormone than slow progressors. In patients with diabetic renal failure, cardiac catheterization revealed reduced stroke work and elevated left ventricular end-distolic pressure during exercise. Autonomic nerve dysfunction and arterial hypertension possibly contributed to the impaired cardiac performance. The existence of a specific diabetic cardiopathy must even be considered. There was a male predominance both in subclinical and manifest diabetic nephropathy. Age at onset of diabetes was lower in micro- as compared to normoalbuminurics. Duration of diabetes had no prognostic implication in subclinical or manifest nephropathy. The mortality rate was high in patients with manifest nephropathy.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Studies of cardiovascular and renal function in subclinical and manifest diabetic nephropathy. 316 65

Cardiovascular, sympathoadrenal, and subjective responses to mental stress induced by a color-word conflict test (CWT) were studied in 30 healthy males before and after intravenous administration of either placebo, beta 1-blockade by metoprolol (0.15 mg/kg), or nonselective beta-blockade by propranolol (0.15 mg/kg). CWT responses were reproducible. Mean arterial pressure increased by 20%. A mainly heart rate-dependent 65% increase in cardiac output (thermodilution) was associated with 25% decreases of both systemic (SVR) and calf vascular (CVR) resistances. Arterial plasma epinephrine (Epi) was doubled, and norepinephrine (NE) increased by 50%. Self-evaluated stress score correlated positively with changes in cardiac output and inversely with changes in SVR during CWT. Both metoprolol and propranolol halved heart rate responses; whereas increases in mean arterial pressure, Epi, and NE were uninfluenced. Metoprolol reduced the increase in stroke volume, and propranolol abolished it. SVR and CVR responses were attenuated by metoprolol and abolished by propranolol. The results suggest that mental stress accelerates the heart through neurogenic mechanisms and that peripheral vasodilatation is achieved through the concerted actions of reduced vasoconstrictor activity and elevated circulating Epi.
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PMID:Cardiovascular and sympathoadrenal responses to mental stress: influence of beta-blockade. 320 6

The first part of this study examined the relationship(s) between Type A behavior scores and heart rate, blood pressure and impedance derived cardiovascular measures in response to discrete stressors during a standardized psychophysiological assessment. Expts. 2A and 2B considered cardiovascular responses to dynamic exercise stress alone and in combination with psychological and cold pressor tests. Gender and stroke volume changes during the psychological stress correlated 0.45 (P less than 0.02) with Type A score. Subscale scores of Job Involvement correlated 0.78 (P less than 0.02) with stroke volume, total systemic resistance and heart rate during the psychological stressor, and systolic blood pressure during the cold pressor task. The combined effects of psychological stress and dynamic exercise on systolic and diastolic blood pressure were significantly greater than the individual effects of these stressors. The use of impedance cardiography in measuring cardiovascular variables that correlate with Type A behavior, during psychophysiological assessments, may further elucidate our understanding of Type A behavior in addition to providing information about how stress interacts with aerobic exercise.
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PMID:Interactive effects of type A personality and psychological and physical stressors on human cardiovascular functions. 322 8

The influence of voluntary physical exercise in running wheels on myocardial function, cardiac oxygen utilization and cardiovascular response to emotional stress was analysed in the spontaneously hypertensive rat. After 6 weeks of exercise, a significant increase in resting cardiac output was found, which was due to an elevation of stroke volume. However, voluntary training for 12 weeks had no effect on resting blood pressure or on the blood-pressure response to mental stress. Cardiac function was also examined in vitro. At a low aortic diastolic pressure, it was markedly augmented in trained spontaneously hypertensive rats. At high aortic diastolic pressure, maximal cardiac function was similar in the two groups. Myocardial oxygen consumption (mumol min-1 g-1) for a given level of external work was reduced in trained, compared with non-exercised control spontaneously hypertensive rats. Chronic physical exercise thus greatly improved myocardial function at a subnormal perfusion pressure, suggesting better nutritional supply to the myocardium, probably created by an increased capillary surface area.
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PMID:Effects of voluntary physical exercise on cardiac function and energetics in spontaneously hypertensive rats. 322 35

This review summarizes briefly the present knowledge on sleep-related factors in ischaemic heart disease. A marked circadian rhythm in the frequency of onset of acute myocardial infarction has been found, but the exact mechanism is not known. The circadian variation is possibly explained by several mechanisms. The best documented is sleep apnoea syndrome, which seems to be a risk factor for ischaemic heart disease and stroke. Stressful REM-sleep seems to be potentially arrhythmogenic in patients with decreased cardiopulmonary function. The role of coronary spasm, increased thrombocyte aggregation and mental stress in sleep disorders is still poorly understood.
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PMID:Cardiovascular stress and sleep. 331 Aug 37

Risk factors for myocardial infarction, sudden coronary death, angina pectoris, stroke and total mortality were analysed in a random population sample of men aged 47-55 years at entry, and followed for 11.8 years. Lipid disturbances, tobacco smoking, elevated blood pressure, diabetes mellitus, obesity, low physical leisure-time activity, psychological stress (for non-fatal events) and excessive alcohol consumption (for fatal events) were the main independent risk factors for coronary heart disease. The attributable risk was also calculated. Uncomplicated angina pectoris was related to dyspnoea during exertion, psychological stress, diabetes mellitus and high relative body weight. Stroke was dependent on elevated blood pressure, tobacco smoking and psychological stress. Quantitatively, the most important risk factors for total mortality were low physical activity during leisure time, tobacco smoking and elevated blood pressure. For patients who had suffered myocardial infarction or angina pectoris, elevated serum cholesterol, elevated blood pressure and tobacco smoking were of prognostic importance. Hypertension, together with lipid disturbances and tobacco smoking, was thus found to be a risk factor both for primary and secondary events, and blood pressure control seems of great importance in preventing these cardiovascular events.
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PMID:Primary and secondary prevention. 347 30

Twenty-four normal subjects were examined during exposure to emotional stress, simulated by mental arithmetic exercise under time shortage and interfering light and sound stimuli. Hemodynamic parameters were determined on the basis of echocardiographic M-records in resting condition and under mental stress. Irrespective of the baseline hemodynamic type, emotional stress produced a hyperkinetic circulatory response. Increased cardiac index resulted from higher heart rate in the presence of unchanged venous return and stroke index. Myocardial contractility increased to a greater extent in individuals with hypokinetic and eukinetic hemodynamics.
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PMID:[Changes in the systemic and intracardiac hemodynamics of healthy persons as affected by emotional tension]. 362 91

Spontaneously hypertensive rats (SHR) were given either 'low' (LNa; 0.5 mmol Na 100 g-1 food), 'control' (CNa; 12 mmol) or 'very high' (vHNa; 120 mmol) sodium diets from 5 to 13-14 weeks of age, to explore how these 240-fold variations in Na intake affected body weight, cardiac, renal and adrenal weights, overall water-electrolyte equilibrium and haemodynamic balance during rest, mental stress and blood loss. Body growth was retarded both in vHNa and LNa SHR presumably reflecting disturbed appetite due to the greatly altered dietary Na contents. Compared with CNa SHR, both cardiac and renal weights 100 g-1 body wt were slightly increased in vHNa and decreased in LNa SHR, with opposite changes of adrenal weights. Total body water, haematocrit and plasma Na-K levels were largely equal in the three groups. Furthermore, cardiac output (CO), stroke volume (SV) and central blood volume (CBV) did not differ significantly between groups; if anything, CO and SV were higher and CBV lower in vHNa and LNa SHR than in CNa SHR. However, while mean arterial pressure (MAP) was only marginally elevated in vHNa compared with CNa SHR, both MAP and total peripheral resistance (TPR) were lowered about 15% in LNa SHR with signs of increased sympathetic activity to the heart also during rest. Despite an apparently normal volume and cardiac output balance in LNa SHR, the latter changes suggest a disturbed neuro-hormonal cardiovascular control.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effects of varying sodium diets on haemodynamics and fluid balance in the spontaneously hypertensive rat. 370 83


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