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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There has been a continuous evolution in hypertensive therapy during the last 30 years. Now, physicians have access to more than 40 agents for treating this widespread condition. Large-scale clinical trials have established that lowering blood pressure in patients with mild to moderate diastolic hypertension results in a decreased incidence of stroke and, to a lesser extent, a reduction in incidence of coronary heart disease [MacMahon SW, Cutler JA, Furberg CD, et al: Prog Cardiovasc Dis 1986; 29 (suppl 1): 99-118]. Even so, the decrease in overall mortality rate is not consistent. Although hypertension occurs with increasing frequency in those over 60 years of age, patients in this age group represent less than 12 percent of the subjects in large trials. Currently, stepped-care is the recommended approach for managing hypertension in patients of all ages. However, the availability of a variety of agents for initial therapy, all with approximately equal efficacy but differing side-effect profiles, calls such an approach into question.
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PMID:The evolution of current hypertension therapy. 304 93

There are few studies devoted specifically to the epidemiology of older hypertensive patients, although some information has been obtained from broader trials in which either the study populations have become older or an older subgroup has been identified. Three areas have been addressed: the changes of blood pressure with age; the prevalence of hypertension in older persons; and the risks of elevated blood pressure in elderly patients. It has been found that blood pressure, especially systolic pressure, increases with age. Consequently, hypertension is extremely prevalent in this age group, affecting 65 percent or more of those over 65 years old, and the phenomenon of isolated systolic hypertension is common. Whereas in the past many physicians treating the elderly have regarded hypertension in these patients as normal and acceptable, or even helpful in ensuring adequate organ perfusion, elevated blood pressure in the elderly is far from benign. Older hypertensive patients' risks of cardiovascular complications and death are from two to five times that of normotensive persons. Treatment of diastolic hypertension in older patients can be expected to delay the onset of cardiovascular disease and improve the quality of life. Hopefully, this will prove to be true for isolated systolic hypertension as well.
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PMID:Epidemiology of hypertension in older patients. 304 94

Long considered a single clinical entity, essential hypertension is now recognized as a heterogeneous spectrum of pathophysiologic disturbances, based on extensive clinical, pharmacologic and biochemical evidence. Two distinctly different mechanisms for long-term vasoconstriction can be identified and quantified in the spectrum of patients with essential hypertension, although the causes of this group of disorders are still obscure. The first vasoconstrictor mechanism is renin-angiotensin mediated and involves an increase in vascular smooth muscle cytosolic free calcium mobilized from intracellular sites. The degree of activity of this mechanism can be assessed by plasma renin level and/or by the hypotensive response to circulating anti-renin-system drugs (such as CEI inhibitors and beta blockers). The second vasoconstrictor mechanism, on the other hand, is renin-independent. It appears to require antecedent renal sodium retention and to be related to abnormal membrane influx of calcium. A low plasma renin level identifies this kind of vasoconstriction, which is also characterized by a low serum ionized calcium. Low-renin vasoconstriction is correctable by sodium depletion or by calcium channel or alpha adrenergic blockade. Depending on the state of sodium balance, these two vasoconstrictor mechanisms contribute reciprocally to maintenance of arteriolar tone in models of experimental hypertension, normotensive and hypertensive people, and in the vasoconstriction of edematous states, such as congestive heart failure. One of the two mechanisms also sustains diastolic hypertension in the experimental and clinical forms of renovascular hypertension and primary aldosteronism. Thus, both experimentally and clinically, at the polar extremes of the range of plasma renin values, one of the two mechanisms predominates: it is possible that, in the medium range of renin values, both mechanisms contribute to vasoconstriction. In our proposed unifying, analytic model, arteriolar vasoconstriction is associated with increased intracellular calcium and decreased magnesium levels in vascular smooth muscle. In the vasoconstriction consequent to sodium-volume expansion, cytosolic calcium is increased by an increased membrane influx. In renin-mediated vasoconstriction, receptor-operated channels mobilize cytosolic calcium instead from intracellular stores. These interrelationships provide a basis for stratifying hypertensive patients pathophysiologically and for applying simpler, more specific, and more rational therapies. Thus, the array of modern pharmacologic agents can often be rationally directed at one or the other, or both, of these two vasoconstrictor mechanisms.
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PMID:Recognizing and treating two types of long-term vasoconstriction in hypertension. 305 33

Results of prospective cohort epidemiological studies in different population groups indicate a constant positive and graded association between the level of systolic blood pressure and subsequent mortality from cardiovascular diseases and stroke, especially with advancing age, and irrespective of the level of diastolic blood pressure. Thus, isolated systolic hypertension in the elderly, defined as systolic blood pressure greater than or equal to 160 mmHg and diastolic blood pressure less than 90 mmHg, is a powerful risk factor for mortality and morbidity. In the Hypertension Detection and Follow-Up Program (HDFP), the multiple logistic analysis of the impact of isolated systolic hypertension on 8-year mortality showed that, in the age group 60-69 years, after adjustment for other factors, there was about a 1% increase in mortality each year for every 1-mmHg increase in systolic blood pressure (P less than 0.05). Similarly, among those screened during the Multiple Risk Factor Intervention Trial (MRFIT), aged 55 years and above, the relative risk of stroke mortality in those with isolated systolic hypertension was 3.0, with a 95% confidence interval of 1.3 to 6.8. The United States National Health Survey data estimate the prevalence of isolated systolic hypertension as 8.5% in the age group 65-74 years. The prevalence of isolated systolic hypertension rises significantly with age (6%, 11% and 18%, respectively in the age groups 60-69, 70-79 and above 80 years). Although treatment of diastolic hypertension in the elderly has been shown to be effective in reducing mortality, no adequate prospective evaluation has yet been completed to determine the efficacy of drug treatment of isolated systolic hypertension. Thus, the question of the efficacy of treatment remains unanswered.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Isolated systolic hypertension in the elderly. 306 88

Two different mechanisms for long-term vasoconstriction that sustain diastolic hypertension in the experimental and clinical forms of primary aldosteronism and renovascular hypertension can also be identified and quantified among patients with essential hypertension. The first is renin-independent, requires antecedent sodium retention, and appears related to abnormal membrane transport of calcium. This vasoconstriction is identified by low plasma renin and ionized calcium values and is correctable by sodium depletion or calcium channel or alpha-blockade. The second is renin-mediated but also involves an increase in cytosolic calcium. This mechanism is quantifiable by the plasma renin level and by the hypotensive response to an anti-renin-system drug (CEI inhibitor, saralasin, beta-blocker). At the very extremes of the range of plasma renin values encountered in hypertensive patients, one of the two mechanisms predominates, whereas in the medium range of renin values either or both mechanisms can be operative.
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PMID:Pathophysiology of diastolic hypertension. 307 77

Hypertension is a pervasive public health problem with enormous economic as well as medical consequences. Progress in developing more effective, safer and more convenient medications has been remarkable. Similarly, progress in focusing public and professional attention on hypertension has led to earlier treatment and undoubtedly contributed significantly to reduced stroke and cardiovascular mortality rates. Challenges in the next decade will be to resolve residual uncertainties about the balance of benefits and risk of treatment in mild diastolic hypertension and isolated systolic hypertension, and to develop incentives for maximizing the cost-effectiveness of treatment in those for whom treatment is, on balance, beneficial. Quality-of-life parameters will play prominent roles in clinical and policy decisions with respect to each of these challenges.
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PMID:Economics in hypertension management: cost and quality trade-offs. 310 2

A blood pressure profile at rest was recorded in 2,000 patients (1,069 females, 931 males) by DINAMAP 845 (from 8 AM to 8 PM. a record every fifteen minute). The limit between normotensive and hypertensive patients in this settled by WHO (BP = 160/95 mmHg). The analysis of percentage of pathological values (BP greater than 160/95 mmHg) allowed us to identify eight type of recordings. Normal (295), Border line hypertension less than or equal 20 p. 100 of pathological values (573), Paroxysmal hypertension (58), hypertension with predominance (963) of whom 484 with systolic predominance and 479 with diastolic predominance, Isolated systolic hypertension (15), Isolated diastolic hypertension (47), hypertension without predominance (15) and Permanent hypertension (82). The variability of blood pressure was studied by using the coefficient of variation = p. 100 of standard deviation/mean.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Blood pressure variation]. 311 2

Paradoxical hypertension is a relatively common complication of surgical repair of coarctation of the aorta. An early phase of systolic hypertension has been ascribed to elevated levels of norepinephrine. Activation of the renin-angiotensin system from sympathetic stimulation has been implicated in a later phase of systolic and diastolic hypertension that can result in mesenteric arteritis. The use of a rapidly acting, titratable intravenous alpha- and beta-adrenergic blocker, such as labetalol hydrochloride, addresses both of these neurohormonal mechanisms. In the intravenous form, it would appear to be an excellent choice for the management of early postoperative hypertension and it can be converted to the oral form in cases of persistent hypertension. We report for the first time the use of labetalol in two young patients for the control of paradoxical hypertension following coarctation repair.
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PMID:Intravenous labetalol for the control of hypertension following repair of coarctation of the aorta. 322 19

Prospectively gathered data from eight geographically defined areas in south-east Asia included serial measures of blood pressure, proteinuria and oedema during pregnancy. A total of 15,476 pregnancies were included. Both antenatal oedema and proteinuria were markers of increased risk of antenatal diastolic hypertension, proteinuric pre-eclampsia and eclampsia. However they identified fetuses at high risk of low birthweight and perinatal mortality only in areas where the incidence of hypertension was low. As a screening strategy to identify women who are at increased risk of antenatal diastolic hypertension, of proteinuric pre-eclampsia and of eclampsia, the most efficient strategy is probably to use the presence of oedema and/or proteinuria. The sensitivity of using this method for identifying women with proteinuric pre-eclampsia is high, but for identifying eclampsia it is still relatively low. Where resources are available there is probably no substitute for using a sphygmomanometer and measuring blood pressure.
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PMID:Could oedema and proteinuria in pregnancy be used to screen for high risk? The WHO International Collaborative Study of Hypertensive Disorders of Pregnancy. 323 84

The relationships between alcohol intake and blood pressure have been examined in 7,735 middle-aged men drawn at random from general practices in 24 British towns. Both mean systolic and diastolic BP are increased in moderate (16-42 drinks/week) and heavy (greater than 42 drinks/week) drinkers. The alcohol-blood pressure relationship is independent of age, body mass index and social class despite their associations with both alcohol intake and BP. The prevalence of hypertension (systolic greater than or equal to 160 mmHg or diastolic greater than or equal to 90 mmHg) is increased in both moderate and heavy drinkers. Non-drinkers have higher rates of diastolic hypertension than occasional or light drinkers, probably due to changes in drinking habits made by those diagnosed as hypertensives. Furthermore, recall of doctor diagnosis of hypertension and of anti-hypertensive treatment is highest among non-drinkers. It is estimated that about 10% of hypertension (systolic or diastolic) can be attributed to moderate or heavy drinking. There is a clear need for increased awareness of the alcohol-blood pressure relationship. Current drinking status should be determined in all hypertensive subjects, and assessment of alcohol effect by temporary withdrawal should be the first step in the management of anyone with sustained hypertension who drinks.
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PMID:Alcohol and blood pressure in middle-aged British men. 324 48


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