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Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mental arithmetic and mirror tracing were compared in 40 untreated patients with borderline hypertension, tested in random sequence in standardized protocols. Both tasks significantly increased systolic and diastolic blood pressure, heart rate, cardiac index, plasma renin, and decreased peripheral resistance. Mental arithmetic also increased cholesterol, triglycerides and HDL; plasma catecholamines were not changed significantly. Lipid changes were correlated with blood pressure changes. These methods will be useful in exploring the relationships between hemodynamic reactivity to stress, and the presence and progression of atherosclerosis, as well as testing the effects of antihypertensive drugs on stress-induced changes that may influence atherosclerotic complications of hypertension.
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PMID:Hemodynamic and endocrine effects of mental stress in untreated borderline hypertension. 226 Nov 52

Applications of control theory in studies of biological system dynamics have come to be called compartmental modelling. A second order, nonlinear, compartmental model is developed which describes the dynamics of the hormone angiotensin II (AII) and arterial blood pressure (BP) during AII infusion experiments. The model is partially identified using dose response data for constant infusion rates between 0.01 and 0.10 microgram/kg/min over a period of several minutes. This study represents a first step in understanding the dynamics of regulation of arterial blood pressure by the renin-angiotensin system. AII is a vasoconstrictor and is known to participate in the natural regulation of BP. AII is also believed to be an agent in the development of hypertension and atherosclerosis. The model is used to identify causal mechanisms which are consistent both with the established correlation between plasma AII concentration and arterial BP and with current physiological knowledge. The study demonstrates how a simple state variable model can be used to provide guidance concerning the design of future infusion experiments.
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PMID:A dynamic model of angiotensin II infusion experiments. 264 70

A variety of age-related anatomic and functional alterations in the kidney have been described. Anatomic abnormalities in the aging kidney include a decrease in kidney size, increased glomerular sclerosis, altered tubular structure, and an altered pattern of vascular flow. These anatomic abnormalities are associated with renal functional abnormalities, including decreased renal blood flow, and glomerular filtration rate. Altered renal tubular function, including impaired handling of water, sodium, acid, and glucose, may also be present. Impaired "endocrinologic" functioning manifested by changes in the renin-angiotensin system, vitamin D metabolism, and antidiuretic hormone responsiveness have been reported. The kidney is constantly exposed to the effects of a variety of potentially toxic processes. These range from environmental toxins and drugs, to a variety of chronic medical illnesses including hypertension, diabetes, and atherosclerotic disease. In this context, differentiation of "aging" effects from nephrotoxic effects resulting from these other processes is difficult. It has been argued that hypertension is an important factor in the development and progression of renal insufficiency in the elderly. The relationship between hypertension, glomerular hyperfiltration, atherosclerosis, and progressive renal dysfunction needs further study. Further research may allow the rational recommendation of interventions designed to control age-associated changes in renal function.
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PMID:Renal function in aging. 266 87

The calcium antagonists, although initially restricted to the treatment of angina pectoris, are now finding widespread application as safe and effective therapy for hypertension. These drugs reduce systemic vascular resistance and thus address the usual primary physiologic defect in high blood pressure. Reduction of blood pressure with these agents appears to lead to the concomitant reduction of hypertension-induced ventricular hypertrophy and improvement of ventricular function. Unlike other vasodilators, calcium antagonists do not secondarily lead to sodium retention or stimulation of the renin-angiotensin-aldosterone and sympathoadrenal systems. They are effective in the treatment of angina pectoris and may inhibit the onset or progression of atherosclerosis. As calcium antagonists primarily block voltage-operated, as opposed to receptor-operated, sarcolemmal calcium channels, they may be rationally and effectively combined with agents such as converting enzyme inhibitors and adrenergic antagonists. Calcium antagonists have important interactions with drugs relevant to the treatment of cardiac disease. The combination of verapamil and beta blockers or disopyramide and diltiazem with amiodarone should be avoided; caution is advised in the concomitant use of calcium antagonists and digoxin or the major antiarrhythmic agents.
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PMID:The actions and role of calcium entry blockers in hypertension: cardiac considerations. 268 25

Fourteen male patients with mild essential hypertension were put on a mackerel and herring diet within a prescribed isocaloric regimen in a cross-over design for 2 weeks. After mackerel diet eicosapentaenoic acid (EPA-C20:5, n-3) appeared more in cholesterol esters (1.7-11.0%), whereas docosahexaenoic acid (DHA-C22:6, n-3) was predominantly incorporated into serum triglycerides (1.0-8.3%). After herring diet, which contained half as much EPA and DHA, their increase was of minor degree. After mackerel diet serum triglycerides, total cholesterol, LDL cholesterol and lecithin cholesterol acyl transferase (LCAT) activity were significantly decreased (by 28%, 9%, 14% and 14%, respectively), returning to the initial levels 3 months later. On the contrary, HDL cholesterol appeared significantly increased (by 12%). After herring diet the differences were not significant. Serum sodium was significantly lower (by 2%) at the end of the mackerel diet as compared to the initial values. On the other hand, uric acid in serum appeared transiently increased (by 24%) at the end of both dietary periods. A significant decrease (by 8%) in casual systolic blood pressure, measured in recumbent position, could be observed only at the end of the mackerel period. Moreover, the level of systolic and diastolic blood pressure before and during a standardized psychophysiological stress test was significantly lower after mackerel diet. Nevertheless, the increments after stress were similar. Plasma renin activity was increased (by 64%) after mackerel diet.(ABSTRACT TRUNCATED AT 250 WORDS)
Atherosclerosis 1985 Aug
PMID:Blood pressure- and lipid-lowering effect of mackerel and herring diet in patients with mild essential hypertension. 300 Mar 95

More than half of the United States population over 65 years of age has essential hypertension. In 1984, there were 10 million elderly hypertensive persons and this number will reach 25 million in the near future. These patients are at high risk for congestive heart failure, stroke, heart attack, and dissecting aneurysm. Successful reduction of blood pressure can lower these risks considerably, but rational treatment depends on understanding the complex pathophysiology of hypertension in older patients. In fact, treatment that does not take into account the combined effects of aging and hypertension on the cardiovascular system and the kidneys may do more harm than the hypertension itself. Among the prominent age-related cardiovascular changes are stiffening of the arterial tree, with or without a contribution from atherosclerosis. This reduces arterial compliance and increases afterload, resulting in the left-ventricular hypertrophy seen in old age and leading to a progressive rise in systolic pressure. There is considerable shrinkage of the kidneys, due primarily to loss of glomerular and tubular tissue in the cortex, along with sclerosis of the glomeruli and formation of tubular diverticula. Arteriolar changes lead to reduced renal blood flow, the shunting of blood around the glomeruli, and thus a reduction in glomerular filtration rate. Renal water and electrolyte excretion are changed, making homeostasis more difficult to maintain, and the renin-angiotensin system is altered, helping to blunt the kidneys' response to pressure changes. Essential hypertension superimposed on all the foregoing effects exacerbates them. Peripheral resistance is usually markedly elevated in older hypertensive persons, which increases afterload directly.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pathophysiology of hypertension in older patients. 304 95

Arterial hypertension (AH) is an excessive elevation of the arterial blood pressure (ABP) in the systemic circulation. It is, however, arbitrary to define a limit between normal and pathological ABP, since the ABP varies in a continuous fashion with the population. Occasional measurement of the blood pressure by sphygmomanometer is rather inaccurate but still remains the method of reference. A more precise determination of the ABP is possible by using the stress blood pressure profile and ambulatory measurement which are prognostically far superior to occasional measurement. AH is not a disease but a risk factor--quantitative and independent of the cardio-vascular system because it contributes to atherosclerosis and regional ischemic processes. The genesis of the so called essential AH still remains unclear, but it is getting better known: from a genetic factor of predisposition, the respective roles of the salt and the kidney as a filter are determining, along with the more or less appropriate action of hormonal factors of the sodium excretion. This is combined with the complex and synergistic action of potent vasopressor mechanisms such as the sympathetic nervous system and the renin-angiotensin systems--circulating as well as in the tissues. AH presents haemodynamic abnormalities, which vary according to age, and among which the elevation of systemic vascular resistances is most characteristic. This is combined with a lack of compliance of the large arterial vessels, and secondarily, a hypertrophy, partially adaptive, of the entire cardiovascular system. This includes left ventricular hypertrophy which has harmful effects on intracardiac and coronary haemodynamics, resulting in an increased mortality. It is therefore necessary that the treatment, not only decrease the blood pressure, but also take into account the regional vascular outputs while respecting and improving the renal, cerebral and coronary circulations with general improvement of the vascular compliance. The treatment must also result in an early and lasting decrease of the myocardial hypertrophy. This is why the new anti-hypertensive treatments (conversion enzyme inhibitors and calcium inhibitors) represent a desirable therapeutic alternative to the classical treatment. Their prescription follows a few general rules, but must, however, remain very personalized with evaluation of the results at two levels: individual control of the ABP and mass benefit in terms of decreased cardiovascular morbidity and mortality.
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PMID:[Essential arterial hypertension. From notion to treatment]. 306 94

Atherosclerosis, aorto-arteritis and fibromuscular dysplasia are the most common causes of vasorenal hypertension. Determination of plasma renin activity is a valuable diagnostic test at early stages of vasorenal hypertension. HLA studies demonstrated significantly elevated antigens B8 and B12 in patients with essential hypertension, and antigen A9 in patients with affected renal arteries. These findings may expand the possibilities of differential diagnosis for the selection of patients, eligible for angiographic investigation. A less than three-years duration of the disease in the presence of high plasma renin activity is a favorable prognostic criterion.
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PMID:[Ways of improving the diagnosis and prognosis in vasorenal hypertension]. 307 42

Data from several epidemiologic studies have suggested that the prevalence of hypertension in patients with diabetes mellitus is approximately 1.5-2.0 times greater than in an appropriately matched nondiabetic population. In patients with insulin-dependent diabetes mellitus (IDDM), hypertension is generally not present at the time of diagnosis. As renal insufficiency develops, blood pressure rises and may exacerbate the progression to end-stage renal failure. In non-insulin-dependent diabetes mellitus (NIDDM), many patients are hypertensive at the time of diagnosis. The incidence of hypertension in NIDDM is related to the degree of obesity, advanced age, and extensive atherosclerosis that is typically present, and it probably includes many patients with essential hypertension. Several other pathophysiologic mechanisms also contribute to the genesis and maintenance of hypertension in the patient with diabetes. Hyperglycemia and increases in total-body exchangeable sodium may lead to extracellular fluid accumulation and expansion of the plasma volume. In some patients, alterations in the function of the renin-angiotensin-aldosterone system and vascular sensitivity to vasoactive hormones may also play a role. It has recently been suggested that hyperinsulinemia and insulin resistance may also contribute to the maintenance of an elevated blood pressure because insulin is known to promote sodium retention and enhance sympathetic nervous system activity. The evidence for these hypotheses and their respective contributions to the etiology of hypertension in IDDM and NIDDM are discussed.
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PMID:Etiology and prevalence of hypertension in diabetic patients. 307 72

A retrospective analysis of peripheral and renal vein plasma renin activity has been performed in 9 patients with bilateral renal artery stenosis (3 fibromuscular dysplasia and 7 atherosclerosis). In all cases angiography showed a reduction of the arterial diameter of more than 70 p. 100. The renal artery was occluded in 3 cases. All patients received a constant sodium diet (100 mEq/day). Peripheral PRA values were classified as normal or low in 6 cases (less than 2.8 ng/ml/h) and high in one case (greater than 2.8 ng/ml/h): this values concerned 2 cases with renal artery occlusion and 1 case with a narrowing of 90 p. 100. Renal venous renin ratio of 1.5 or more has been found in 8 cases. In one case, the stenosis was quite symmetrical (70 p. 100) and the ratio less than 1.5. The secretion index has been calculated as the ratio between the venoarterial difference of both affected and unaffected side over the arterial value of PRA (V-A/A). On the more stenosed side, was found a V-A/A ratio of 0.5 or more. This ratio is particularly high in case of artery thrombosis, but there is no correlation between the ratio and the degree of stenosis. On the contralateral side, where the lesions were less important, the V-A/A ratio was low, ranging from 0 to 0.2; this estimation of renin secretion was found despite a significant stenosis on the angiography. 7 patients underwent PTA or surgery. 2 kidneys with arterial thrombosis were nephrectomized. In 5 cases the surgical treatment is performed on the 2 sides during the same procedure.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Lateralization of renin secretion in renovascular hypertension with bilateral arterial stenosis]. 314 9


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