Early association of sympathetic overactivity, hypertension, insulin resistance, and coronary risk.

Whereas this review is based on the available evidence, interpretation of the data is entirely hypothetical and subjective. To a large degree the review reflects our long-standing fascination with the role of the sympathetic overactivity in hypertension. The basic tenet is that sympathetic overactivity in hypertension may lead to a number of secondary changes, all of which are conductive to coronary heart disease.

Home blood pressure monitoring: advantages and limitations.

Home blood pressure monitoring is a useful tool for clinical management of patients with hypertension. Its major advantages are the ease with which the techniques can be learned, reproducibility of values, sensitivity of measurement and availability of normotensive data. In spite of the ability to tell whether a subject has normal or abnormal values, because of the lack of prospective mortality/morbidity data, home blood pressure monitoring cannot be used to decide whether treatment is indicated.

Predictors of blood pressure and hypertension. General principles.

Early intervention in the treatment of hypertension can reduce the detrimental effects of high blood pressure. Therefore it is important to be able to predict the development of hypertension in individuals. A number of factors can be used as predictors of hypertension, but only childhood high blood pressure (especially in combination with obesity) is a potent predictor of future hypertension.

Clinical implications of pathophysiologic changes in the midlife hypertensive patient.

Both aging and hypertension decrease cardiac output through a lower stroke volume and a diminished beta-adrenergic responsiveness. In parallel, the vascular resistance increases because of vascular hypertrophy. In addition, in hypertension the alpha-adrenergic responsiveness is enhanced.

Linkage of MN locus and erythrocyte lithium-sodium countertransport in Tecumseh, Michigan.

Human essential hypertension is a family of diseases; one subtype has an increased maximum velocity for red blood cell lithium-sodium countertransport activity. To begin the localization of the gene or genes responsible for this phenotype, we examined the association of blood pressure, lithium-sodium countertransport, and two genetic markers previously associated with hypertension--the MN blood group antigen (chromosome 4) and the plasma protein haptoglobin (chromosome 18)--in a population-based sample of 592 young adults from Tecumseh, Mich., the site of an ongoing cardiovascular epidemiological investigation.

Quinapril, an angiotensin converting enzyme inhibitor, prevents cardiac hypertrophy during episodic hypertension.

Six control dogs, six dogs treated with 1.5 mg/kg b.i.

Changes in left ventricular diastolic filling during the development of left ventricular hypertrophy: observations using Doppler echocardiography in a unique canine model.

To examine changes in diastolic left ventricular filling during the development of left ventricular hypertrophy, serial pulsed Doppler echocardiographic studies were performed in a canine model of left ventricular hypertrophy induced by neurogenic pressor episodes. This model is unique since left ventricular hypertrophy develops without sustained hypertension. The neurogenic pressor episodes produced progressive increases in left ventricular mass of 17% by 3 weeks (p less than 0.

Red blood cell lithium-sodium countertransport in the tecumseh blood pressure study.

Human essential hypertension has more than one cause, but to dissect out subtypes, markers are required. The maximal activity of red blood cell lithium-sodium countertransport has been shown to be increased in hypertensive patients in case-control and population-based studies; in the latter, its distribution is a mixture of two overlapping but distinguishable subpopulations. In the present study, we classified 705 participants in the Tecumseh Blood Pressure Study as having either normal (mean, 0.

Autonomic nervous system dysregulation in human hypertension.

An increased sympathetic drive combined with decreased parasympathetic inhibition is found in patients with borderline hypertension, who characteristically have rapid heart rates, high cardiac output and relatively normal vascular resistance (hyperkinetic state). In established hypertension, cardiac output is normal, vascular resistance is elevated and signs of increased sympathetic drive are absent. Apparently hemodynamics and sympathetic drive change during hypertension.

Independence of pressure reactivity from pressure levels in Tecumseh, Michigan.

The relation between blood pressure level and reactivity to mental arithmetic and isometric exercise was investigated in 169 men and 120 women (average age, 32.3 years) from the village of Tecumseh, Mich. In the entire population, the correlation between baseline blood pressure and blood pressure response to both stressors was not significant.

Autonomic nervous dysfunction in essential hypertension.

Borderline hypertension, a condition in which the blood pressure oscillates between normal and high values, is a predictor of future more severe hypertension. Pathophysiologically, borderline hypertension is different from established hypertension. A large proportion of such patients have elevated cardiac output and a normal vascular resistance.

Hyperkinetic borderline hypertension in Tecumseh, Michigan.

Of 691 healthy (untreated) villagers of Tecumseh, Michigan (average age 32.6 years), 99 had a clinical blood pressure exceeding 140/90 mmHg. Thirty-seven per cent of these borderline hypertensives had increased heart rate, cardiac index, forearm blood flow and plasma norepinephrine.

Platelet function during antihypertensive treatment with quinapril, a novel angiotensin converting enzyme inhibitor.

The effect of various antihypertensive medications on platelet function is of increasing interest. Conflicting effects of captopril on platelet function are reported and the impact of angiotensin converting enzyme (ACE) inhibitors not containing a sulfhydryl group such as enalapril, lisinopril, and quinapril on platelet function remains unstudied. Therefore, the aim of the present study was to examine the effect of antihypertensive treatment with quinapril, a novel ACE inhibitor not containing a sulfhydryl group, on platelet function.

"White coat" versus "sustained" borderline hypertension in Tecumseh, Michigan.

During a survey of young subjects not receiving treatment for hypertension in Tecumseh, Michigan, clinic and self-monitored blood pressures taken at home (14 readings in 7 days) were obtained in 737 subjects (387 men, 350 women, average age 31.5 years). Hypertension in the clinic was diagnosed if the clinic blood pressure exceeded 140 mm Hg systolic or 90 mm Hg diastolic.

Validation of non-invasive measurement of cardiac output. The Ann Arbor experience.

In an assessment of non-invasive methods for the clinical measurement of cardiac output, both M-mode echocardiography and the CO2 rebreathing technique were found to be unreliable. However, the echo-Doppler method appeared for population studies.

Changing role of the autonomic nervous system in human hypertension.

Pathophysiological effects of the autonomic nervous system are clearly seen in young patients with a high cardiac output and borderline hypertension. As the hypertension progresses, there is a change from the hyperkinetic circulation in borderline hypertension to the increased vascular resistance seen in established hypertension. This hemodynamic transition is caused by decreased beta-adrenergic responsiveness and decreased end-diastolic distension of the heart combined with an increased alpha-adrenergic responsiveness of the resistance vessels.

The association of borderline hypertension with target organ changes and higher coronary risk. Tecumseh Blood Pressure study.

The Tecumseh project investigates the evolution of hypertension in a healthy population. Of 946 subjects aged 18 through 38 years, 124 had clinic blood pressure readings higher than 140/90 mm Hg (the mean for borderline hypertensive subjects was 130/94 mm Hg). Compared with normotensive subjects, borderline hypertensive subjects had higher home blood pressures (mean, 12/7 mm Hg higher).

Hemodynamic effects of quinapril, a novel angiotensin-converting enzyme inhibitor.

The hemodynamic effects of quinapril, a novel nonsulfhydryl-containing angiotensin-converting enzyme (ACE) inhibitor, were assessed in 10 patients with mild-to-moderate essential hypertension. Compared with placebo, quinapril (20 mg) administered twice daily for 4 weeks significantly lowered blood pressure by decreasing total peripheral resistance without producing tachycardia, an increase in cardiac output, or a rise in plasma catecholamines. Quinapril significantly reduced renal, but not forearm, vascular resistance.

The Tecumseh Blood Pressure Study. Normative data on blood pressure self-determination.

In Tecumseh, Mich, we obtained blood pressure (BP) self-determination data in 608 healthy adults (327 men, 281 women; average age, 32.6 +/- 3.5 years) representing a wide range of educational backgrounds.

Disease entities, mixed multi-normal distributions, and the role of the hyperkinetic state in the pathogenesis of hypertension.

This paper concerns the theory and relevance of finite mixtures of univariate and multivariate normal distributions in medical research and suggests that multivariate normal mixture analysis, hitherto not extensively explored, is an appealing approach to the investigation of etiologically obscure, multifactorial diseases such as hypertension. We elaborate a statistical strategy to resolve and test for a normal mixture distribution in a seemingly heterogenous population actually comprising homogenous subpopulations. We use this strategy to validate the hypothesis that in the population at large there is a subgroup of individuals with the characteristic of a hyperkinetic circulatory state, defined as the association of an elevated cardiac index or heart rate with high blood pressure.

Predictors of blood pressure and hypertension in Tecumseh, Michigan.

Correlates of present blood pressure status are analyzed in 576 subjects (271 males, average age 32 years) in Tecumseh, Michigan. In addition to the current values, anthropometric and blood pressure data are available when the subjects were, on average, 6.9 and 22.

Are different hemodynamic patterns of antihypertensive drugs clinically important?

Since vascular resistance is elevated in hypertension, it is suggested that vasodilators lower the blood pressure by a physiologic mechanism and therefore must be more useful than cardiac output-lowering drugs. This is not entirely correct. Drugs that lower cardiac output are also relative vasodilators, but the vasodilation occurs at a lower level of cardiac output.

Hemodynamic and neurohumoral evidence of multifaceted pathophysiology in human hypertension.

As hypertension advances, secondary pathophysiologic changes are induced in multiple organs. Consequently, we investigated the pathophysiology of the earliest forms of hypertension--e.g.