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 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exaggerated cardiovascular reactivity to psychological stress is a potential pathophysiological mechanism linking behavior and cardiovascular disease. Because of the recognized gender differences in incidence of cardiovascular disease, potential gender differences in cardiovascular reactivity to laboratory stressors have been evaluated. The current study examined the cardiovascular responses of a total of 42 young women (N = 22) and men (N = 20) undergoing a laboratory protocol including the following: a nonverbal math task, a mirror tracing task, the Stroop Color-Word interference task, and an isometric handgrip task. In addition to the assessment of heart rate and blood pressure, cardiac output, stroke volume, total peripheral resistance and preejection period were assessed by impedance cardiography. A number of personality characteristics that vary in prevalence by gender were also measured to evaluate their ability to explain potential gender differences in cardiovascular responses. Results indicated that men responded with greater total peripheral resistance and systolic and diastolic blood pressure responses than did women on a subset of tasks, whereas women exhibited larger increases in heart rate on a subset of tasks. Thus, men were more likely to be "vascular" reactors, with women being more likely to be "cardiac" reactors. Personality characteristics did differ between men and women, but did not explain significant variance in the gender differences in cardiovascular responses. We conclude that additional studies should focus on experimental manipulations of potential physiological mechanisms responsible for these differences, such as reproductive hormones.
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PMID:Hemodynamic adjustments to laboratory stress: the influence of gender and personality. 831 Jan 11

Optimal antihypertensive therapy should control blood pressure at rest and during stress while preserving the physiologic hemodynamic response. In patients with mild to moderate hypertension, the hemodynamic profile and catecholamine response at rest, during isometric, mental, and orthostatic stresses were compared before and 12 weeks after angiotensin-converting enzyme inhibition or calcium channel blockade. Antihypertensive therapy was titrated either with the angiotensin-converting enzyme inhibitor fosinopril (10 to 40 mg; n = 9) or with the calcium antagonist isradipine (5 to 20 mg; n = 10) until diastolic blood pressure < 90 mm Hg was achieved. Groups were comparable in race, sex, body mass index, pretreatment mean arterial pressure and response to isometric stress (25% increase in mean arterial pressure) before treatment. At rest, total peripheral resistance was reduced to the same extent (18%) in both groups. After fosinopril, the percent increase in stroke volume was higher and heart rate lower than with isradipine. During isometric stress, the percent increase in mean arterial pressure and cardiac output was higher, with isradipine (p < 0.05) reaching pretreatment levels. Plasma catecholamines were also higher with isradipine (p < 0.05), increasing by 100% with plasma norepinephrine compared with 16% before treatment. During orthostatic stress significant reductions in mean arterial pressure and stroke volume were observed after isradipine but not after fosinopril. Neither medication significantly modified the response to mental stress. Our data suggest that despite a comparable reduction in total peripheral resistance at rest, fosinopril preserves a more physiologic hemodynamic response to isometric and orthostatic stress than isradipine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Disparate cardiovascular response to stress tests during isradipine and fosinopril therapy. 836 73

The aim of the present study was to evaluate the variation in left ventricular function at 15 and 120 days after bypass surgery. Ten male patients (mean age 59.6 +/- 7 years) with previous myocardial infarction and coronary stenosis of at least two main vessels, underwent a radionuclide ambulatory monitoring of left ventricular function (VEST) during: handgrip test, mental stress test, walking, climbing stairs. These tests were carried out 8 +/- 2 days before (T0), 15 +/- 3 days (T1) and 120 +/- 11 days after coronary bypass; heart rate (HR), ejection fraction (EF), stroke volume (SV), and cardiac output (CO) were evaluated beat by beat before and during the test until the maximal HR was reached. Handgrip and mental stress tests did not induce significant variations in cardiac indices both before and after cardiac surgery. No variation in HR was observed before and after the test. During walking, at T0, HR increased from rest to maximal effort (p < 0.01) with a significant decrease in EF (p < 0.05); at T1 HR, EF, SV and CO increased with respect to rest (p < 0.01); AT T2 HR, EF (p < 0.05) and CO (p < 0.01) increased with respect to rest. Climbing stairs, at T0, HR increased (p < 0.01) and EF decreased (p < 0.05); at T1 HR, EF, CO (p < 0.05) and SV (p < 0.01) increased with respect to rest. At T2 an increase in HR (p < 0.01) and CO (p < 0.05) was observed at maximal effort with respect to rest. The statistical analysis on the percentage variations between baseline and maximal effort (climbing stairs) showed a significant increase in SV at T2 compared to T0 (p < 0.01). In conclusion, VEST during daily normal activities 15 days and 4 months after bypass surgery showed a significant increase in cardiac function indices. The best results obtained at T1 can be explained with the transient increase in adrenergic tone at the time of early postoperative period.
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PMID:[The short- and medium-term ambulatory radionuclide study of left ventricular function (VEST) after aortocoronary bypass]. 854 18

Men at risk for development of hypertension may show elevated blood pressure at rest and during work on mental stressors. We examined which component of blood pressure, vascular resistance or cardiac output, accounted for raised blood pressures seen in a high-risk, normotensive sample. Parental history of hypertension and resting systolic blood pressures were used to categorize subjects into high (n = 19) and low (n = 14) risk groups. Blood pressure, heart rate, cardiac output, stroke volume, and vascular resistance were measured during rest, mental arithmetic, and reaction time. Compared to low risk subjects, the high risk men had significantly higher blood pressures accompanied by higher vascular resistances at rest and during mental stress. The groups had negligible differences in heart rate, stroke volume, and cardiac output. This pattern of results implicates vascular resistance as the dominant element in altered blood pressure control in these young men at high risk for hypertension.
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PMID:Men at risk for hypertension show elevated vascular resistance at rest and during mental stress. 910 42

Psychological stress has been implicated as a risk factor for a number of medical conditions. The association has been particularly well-studied for coronary heart disease. In contrast, there are only a few studies regarding the role of psychological stress as a risk factor for stroke. Additional research is clearly necessary to better delineate the degree of risk and the physiological mechanisms through which psychological stress may play a role in the development of cerebrovascular disease.
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PMID:Is psychological stress a risk factor for cerebrovascular disease? 926 33

We studied the relationships of cardiovascular reactivity during mental stress with left ventricular mass index in a group of prepubertal children 8 to 10 years old and in a group of peripubertal or postpubertal adolescents 15 to 17 years old. One hundred fifteen participants, varying in age group, sex, and race (black and white), took part in a laboratory stress protocol consisting of a reaction-time task, a mirror tracing task, a cold forehead challenge, and a stress interview. Cardiovascular measures included blood pressure and heart rate, as well as cardiac output, stroke volume, total peripheral resistance, and preejection period obtained noninvasively with impedance cardiography. Measures of left ventricular mass were made by echocardiography. Results indicated that across all participants, left ventricular mass index was associated with cardiovascular responses during the mirror tracing and cold forehead tasks, especially with those responses reflecting increased vasoconstriction. Subgroup analyses showed that these associations were significant for males and sometimes adolescents but not for females and children. As mirror tracing and cold forehead tasks most consistently produce alpha-adrenergic activation, the results suggest a model in which vasoconstriction due to mental stress is related to increased left ventricular mass in susceptible individuals, even at a young age.
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PMID:Cardiovascular reactivity to stress and left ventricular mass in youth. 933 73

Until recently, there has been little evidence substantiating the belief that mental stress provokes myocardial infarction and stroke, and aggravates atherosclerosis. However, recent advances in methodology for demonstrating effects of stress are now beginning to build a foundation of evidence that supports those beliefs. In monkeys, social stress doubles coronary atherosclerosis, and increases coronary spasm, and treatment with oestrogen, which improves endothelial function, reduces coronary spasm in relation to stress. In human beings, mental stress provokes myocardial ischaemia, and haemodynamic responses to mental stress predict progression of left ventricular enlargement, and progression of carotid atherosclerosis. These findings suggest that it may not be safe to withhold treatment of high office pressures in patients with white coat hypertension. There is now some evidence that stress management in the form of individualized cognitive behavioural interventions reduces blood pressure. Further work is needed to determine whether it is safe to withhold treatment in white-coat syndrome, and whether stress management can reduce atherosclerosis and ischaemic events.
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PMID:Neurocardiology. Stress and atherosclerosis. 948 93

The two most common causes of vascular dementia (VAD) are dementia evolving in connection with multiple small or large strokes and dementia related to ischemic white-matter lesions (WMLs) of the brain. The knowledge about risk factors for these disorders is still scarce. Besides sharing risk factors with stroke, dementia with multiple small or large brain infarcts is also associated with non-vascular risk factors such as high alcohol consumption, psychological stress in early life, lower formal education, blue collar occupation, and occupational exposures. Risk factors for dementia in stroke victims include stroke-related and non-stroke related risk factors. Non-stroke-related factors are similar to those found in Alzheimer's disease. The main risk factors for ischemic WMLs are hypertension or increased blood pressure, but WMLs have also been associated with a number of other vascular risk factors. In recent years, Alzheimer's disease (AD) has also been reported to be associated with vascular risk factors, including hypertension, coronary heart disease, atrial fibrillation, diabetes mellitus, and WMLs. Although these associations may reflect an overdiagnosis of AD in cases with silent cerebrovascular disease, or that cerebrovascular disease increases the possibility that individuals with Alzheimer lesions will express a dementia syndrome, there are also alternative explanations. AD and cerebrovascular disease may for instance share similar risk factors or etiologic pathways. The pathogenetic implications for the association between AD and vascular factors need to be further explored. There is also a need for more studies on risk factors for VAD and risk factors for dementia in stroke samples, as well as studies on non-vascular risk factors for ischemic WMLs.
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PMID:Status of risk factors for vascular dementia. 954 18

Individuals differ in the cardiac and vascular processes that underlie blood pressure elevations evoked by environmental stimuli; such differences may reflect variability in sympathoadrenal response. We separated 108 healthy, young-adult males into those with predominant elevations in either cardiac output or peripheral resistance when exposed to psychological challenges. We then asked if they differed on other measures of cardiovascular response, concomitant plasma catecholamine reactions or 24-h urinary excretion of catecholamines. Cardiac reactors, relative to vascular reactors, showed reduced cardiac pre-ejection period, a smaller reduction in stroke volume, and elevated plasma epinephrine response and 24-h urinary epinephrine excretion. Vascular reactors, relative to cardiac reactors, responded to mental stress with more elevated diastolic blood pressure, a rise in peripheral resistance and pulse wave velocity, and a greater reduction in stroke volume. Vascular reactors, however, did not show plasma norepinephrine response or 24-h urinary norepinephrine excretion that was greater than cardiac reactors. The results provide partial support for the hypothesis that variability in sympathoadrenal activity contributes to individual differences in cardiac and vascular reactivity, and extend prior observations by demonstrating covariation of behaviorally-elicited cardiac reactivity with the 24-h excretion of epinephrine.
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PMID:Behaviorally-evoked plasma catecholamine response and 24-hour excretion of urinary catecholamines among cardiac and vascular reactors. 1068 72

Our long-term objective is to identify genes whose expression results in hypertension and in phenotypic changes that may contribute to hypertension. The purpose of the present study was to describe evidence for the heritability of hypertension-related phenotypes in hypertensive, hyperlipidemic black sib pairs. Outpatient anthropomorphic measurements were obtained in >200 affected sib pairs. In addition, 68 of these sib pairs were studied under controlled, standardized conditions at an inpatient clinical research center while off both antihypertensive and lipid-lowering medications. Heritability was estimated on the basis of sib-sib correlations and with an association model. Higher heritability estimates for blood pressure were observed with multiple measurements averaged over 24 hours than with measurements at a single time point, and heritability estimates for nighttime blood pressures were higher than those for daytime blood pressures. Heritability estimates for several of the phenotypes were augmented by obtaining measurements in response to a standardized stimulus, including (1) blood pressure responses to the assumption of upright posture, standardized psychological stress, and norepinephrine infusion; (2) plasma renin, aldosterone, epinephrine, and cAMP and cGMP responses to the assumption of upright posture; (3) para-aminohippurate and inulin clearances in response to norepinephrine infusion; and (4) plasma arginine vasopressin in response to NaCl infusion. High heritability estimates were also observed for various measures of body size and body fat, left ventricular size, cardiac index, stroke volume, total peripheral resistance, and serum concentrations of LDL and HDL cholesterol and leptin. These heritability estimates identify the hypertension-related phenotypes that may facilitate the identification of specific genetic determinants of hypertension in blacks with hyperlipidemia.
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PMID:Genetic determinants of hypertension: identification of candidate phenotypes. 1090 5


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