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

The history of research on the "structural factor" in primary hypertension is briefly reviewed, and the gradual realization of its important influence on the hemodynamics of hypertension is outlined, as seen from a "personal angle." Experiences from previous studies of normal vascular function in animals were decisive for our first hemodynamic demonstration concerning the "structural upward resetting" of the systemic resistance vessels in human primary hypertension. Subsequent quantitative studies in rats with primary and secondary hypertension complemented these studies, confirming that the critical structural changes are a rapid increase in precapillary resistance at full dilatation associated with an increase in wall/lumen ratio due mainly to media hypertrophy and occurring in both primary and renal hypertension. Analyses were also performed concerning cardiac, barostat, and venous structural resettings, which are briefly mentioned. In our first studies of human primary hypertension, we suggested that the structural factor might itself be genetically reinforced, and increasing evidence in favor of this view is now accumulating. It is further discussed how antihypertensive therapy should be directed primarily against the structural upward resetting, as dependent on the local pressure and "trophic" influences, and some of our results in rat models are outlined. Finally, as the structural factor at the systemic resistance level also invites positive feedback interactions with functional "pressor" influences, it is, in a way, more difficult to explain why 85-90% of people remain normotensive than how hypertension gradually develops in 10-15% of people. This points to some powerful and durable negative feedbacks, which are still poorly understood, because most so far known barostats are readily reset upward in hypertension. It is here that the Muirhead renomedullary depressor system, and perhaps also the unmyelinated baroreceptor-volume receptor afferents, may be of particular importance.
Hypertension 1990 Jul
PMID:"Structural factor" in primary and secondary hypertension. 236 48

A study was made of the relationship between Na-Li countertransport and arterial blood pressure in 95 persons selected at random from the representative sample (n = 1716) of the population of one of the districts of Moscow. Of these, 34 persons turned out to be normotensive, 15 had borderline hypertension, 44 stable essential hypertension, and 2 persons presented with secondary hypertension. A positive correlation was found between countertransport and age and weight, determining 20.4% of interindividual variability of countertransport values. The mean value of countertransport in the hypertension group appeared much higher than in the normotensive group, both without and with regard to the correlating parameters. Repeated examinations demonstrated that the countertransport value in each person remained unchanged for two years. A nonlinear correlation was discovered between countertransport and arterial blood pressure. The rate of countertransport is not related to arterial blood pressure (low and high values). A dramatic change in the countertransport values occurred within a narrow borderline range of arterial blood pressure.
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PMID:[The relation of arterial pressure and the rate of Na-Li countertransport in a representative subsample of the population of Moscow residents]. 239 73

An integrated approach, progressively implemented in the ARTEMIS system since 1975, is described for the computerized management of hypertensive patients. From a medical point of view, computerized programs can be used to memorize patients' individual records and profiles, to facilitate patient management and follow-up, to store medical knowledge about hypertension and to provide facilities for decision making at the level either of the individual patient or of the population followed up. From a technical point of view, the methodology used integrates data and knowledge management facilities into the same software. Five hypertension clinics are presently using the system in France and more than 22,000 records have been registered. Answer rates to 12 mandatory questions regarding past history and examination at first visit were superior to 95% in 19,601 records created between January 1976 and December 1987. Patient database interrogation can be used to evaluate the sensitivity and specificity of various signs and symptoms for the diagnosis of secondary hypertension, and to predict, for each patient, his/her cardiovascular risk, the risk of drop-out, the risk of insufficient blood pressure control and the probable blood pressure level. It also serves to test the content and validity of the associated expert system which is progressively built up. A prospective evaluation of the performance of the expert system on 80 cases of hypertension showed overall agreement between the specialists and the expert system ranging from 58 to 91% depending on the decision.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Computer-assisted techniques for evaluation and treatment of hypertensive patients. 240 67

Ketanserin is a 5-HT2 antagonist with alpha-adrenoreceptor blocking activity. This study examines the efficacy and safety of ketanserin in the control of severe primary and secondary hypertension, including renal hypertension. Patients with uncontrolled hypertension were admitted to hospital and entered the study if the supine diastolic blood pressure phase V (SDBP) was greater than 110 mm Hg after 2 h continuous BP monitoring (Dynamap). Ketanserin was administered as an intravenous (i.v.) 5 mg bolus every 60 s until SDBP fell greater than 15 mm Hg or maximum dose (30 mg) was reached, then by i.v. infusion at 4-20 mg/h to maintain SDBP fall greater than 15 mm Hg over 6 h. Twenty five patients were monitored and 20 (seven men, 13 women, ages 14-65 years) fulfilled the entry criteria. Seventeen of 20 were on antihypertensive medication, and 14 had underlying renal disease. Preinjection mean BP was 188/123 mm Hg for the 20 patients, falling at 5 min to 175/103 mm Hg. Supine diastolic blood pressure fell greater than 15 mm Hg in 16 of 20 patients. In these patients, BP remained satisfactorily controlled over the 6-h ketanserin infusion. Heart rate was unchanged. The four patients who did not respond were receiving the alpha-blocker prazosin, but seven other patients on high-dose prazosin did respond. We conclude that i.v. ketanserin is effective in the acute management of severe hypertension, including hypertension secondary to renal disease.
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PMID:Ketanserin in the acute management of severe hypertension. 241 44

Renal artery stenosis is one of the most important forms of secondary hypertension. For years, the only causative treatment was nephrectomy. With rapid advances in cardiovascular and transplantation surgery, operative procedures in renovascular hypertension become more and more sophisticated. Revascularization is superior to medical management of renovascular hypertension in terms of preserved renal function. In recent years, surgical result have been excellent, and even patients with rather complex forms of renovascular hypertension have been successfully operated upon. New classes of antihypertensive drugs, particularly beta-blockers and angiotensin I converting enzyme inhibitors, have enabled the control of blood pressure in most patients with renovascular hypertension but do not assure preservation of renal function. Finally, a fascinating technique, the percutaneous transluminal renal angioplasty, has rapidly advanced to become one of the most popular methods in the treatment of hypertension secondary to renal artery stenosis. However, percutaneous transluminal renal angioplasty is the treatment of choice for most nonostial, nonocclusive lesions.
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PMID:[Renovascular hypertension]. 252 91

To assess the hemodynamic characteristics in malignant hypertension, echocardiography was performed in 18 patients with malignant essential hypertension (MH-I, n = 9) and secondary hypertension (MH-II, n = 9). Patients with benign hypertension with or without left ventricular hypertrophy (n = 8 and 7, respectively), patients with hypertensive heart failure (n = 7) and normotensive volunteers (n = 10) were subjected to controls. Plasma noradrenaline (NA) and renin activity (PRA) were also measured prior to the antihypertensive therapy. There were no significant differences in the durations of hypertension before the malignant phase, and the mean arterial pressure between MH-I and MH-II. Although posterior wall thickness (PWTd) in MH-II was similar to that in MH-I, interventricular septal thickness (IVSTd) was less marked in MH-II. The plasma NA and PRA were markedly increased in both MH-I and MH-II. End-diastolic dimension (Dd) of the left ventricle was within normal range, but end-systolic dimension (Ds) was significantly increased in MH-I, MH-II and hypertensive heart failure. The moderate decreases in ejection fraction (EF) and mean velocity of circumferential fiber shortening (mVcf) were observed in both MH-I and MH-II. Marked decreases in EF and mVcf were also observed in patients with hypertensive heart failure. The relationship between systolic blood pressure and Dd/PWTd was shifted toward the right and upper portion of the normal relation in MH-I and MH-II. The present study demonstrated that the hemodynamic characteristics in malignant hypertension are an inappropriate left ventricular hypertrophy due to a marked increase in systolic stress; dilatation of the left ventricle in systole; and a moderate decrease in ventricular systolic function. It is suggested that a decrease in left ventricular systolic function in malignant hypertension might be due in part to a marked increase in the influence of neurohumoral factors on hemodynamics.
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PMID:[Echocardiographic features of left ventricular hypertrophy and contractility in malignant hypertension]. 253 Mar 33

Radioimmunoassay was used in 39 patients with chronic glomerulonephritis and secondary hypertension to measure atrial natriuretic peptide concentration in blood plasma. The latter concentration appeared unrelated to the patients' age, duration and gravity of hypertension, the degree of renal insufficiency, hyperhydration and activation of renin-angiotensin-aldosterone++ system. The conclusion is made on minor contribution of this short-acting peptide to pathogenesis of arterial hypertension in chronic glomerulonephritis.
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PMID:[The role of atrial natriuretic peptide in the pathogenesis of arterial hypertension in chronic glomerulonephritis]. 253 5

1. Erythrocyte Na+ transport (Na+ pump activity, co-transport, countertransport and passive Na+ efflux) and intracellular Na+ concentration were studied in 10 normal individuals and in 29 uraemic patients on chronic haemodialysis, before and after a haemodialysis session. Eight of them fulfilled the criteria of hypertension. 2. Normotensive patients before haemodialysis were classified in two groups: group 1 (pump-) with decreased erythrocyte Na+ pump activity, and group 2 (normal pump) with normal erythrocyte Na+ pump activity. Group 1 showed, compared with controls, a normal intracellular Na+ concentration and a decreased co-transport, but no difference in either countertransport or passive Na+ efflux. After haemodialysis this difference disappeared. Before haemodialysis, group 2 showed a high intracellular Na+ concentration, but activities of the Na+ transport systems studied were similar to those of controls. After haemodialysis, cell Na+ concentration decreased to a level not significantly different from that of controls. 3. Both before and after haemodialysis, hypertensive patients showed Na+ transport system activities and an intracellular Na+ concentration similar to those of controls. 4. Endogenous digoxin-like immunoreactivity (EDLI) and erythrocyte Na+ transport were studied in five normotensive and five hypertensive patients, before and after haemodialysis. EDLI in plasma was similar in both groups before and after haemodialysis. No correlation was found between EDLI and erythrocyte Na+ pump activity. 5. These results suggest the existence in some dialysed uraemic patients of alterations in erythrocyte Na+ fluxes, which may be corrected by haemodialysis. EDLI and erythrocyte Na+ fluxes do not seem to be markers of secondary hypertension in these patients.
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PMID:Endogenous digoxin-like immunoreactivity and erythrocyte sodium transport in uraemic patients undergoing dialysis. 253 91

An estimated 58 million Americans are at increased risk of morbidity and premature death due to high blood pressure (BP) and require some type of therapy or systematic monitoring. This article focuses on recent advances in our understanding of the pathogenesis of hypertension, new approaches to the diagnosis and treatment of secondary hypertension, and current views of the most appropriate nonpharmacologic and pharmacologic therapy for essential hypertension. In view of the extremely high prevalence of the disorder, emphasis is placed on efficient and cost-effective strategies for diagnosing and managing the hypertensive patient. Recent evidence indicates that nonpharmacologic therapy, including dietary potassium and calcium supplements, reduction of salt intake, weight loss for the obese patient, regular exercise, a diet high in fiber and low in cholesterol and saturated fats, smoking cessation, and moderation of alcohol consumption produces significant sustained reductions in BP while reducing overall cardiovascular risk. Accordingly, nonpharmacologic antihypertensive therapy should be included in the treatment of all hypertensive patients. In persons with mild hypertension, nonpharmacologic approaches may adequately reduce BP, thereby avoiding the expense and potential side effects of drug therapy. In patients with more severe hypertension, nonpharmacologic therapy, used in conjunction with pharmacologic therapy, can reduce the dosage of antihypertensive medications necessary for BP control. Patients treated with nonpharmacologic therapy only should be followed closely, and if BP control is not satisfactory, drug therapy should be added. The large number of drugs available for use in hypertension treatment, coupled with our rapidly expanding knowledge of the pathophysiology of hypertension and of the adverse effects of these drugs in individual patient groups, make it possible to individualize antihypertensive treatment. When used as monotherapy, most agents effectively lower BP in the majority of patients with mild or moderate essential hypertension. Thus, a single agent from one of four classes: diuretics, angiotensin-converting enzyme inhibitors, calcium channel blockers, and beta-adrenergic blockers, usually provides effective BP control with minimal side effects in most patients. Therapy should be initiated with the agent most likely to be effective in BP lowering and best tolerated. If the initial agent is ineffective at maximal recommended therapeutic doses or has undue side effects, an alternative agent from another class should be tried. When monotherapy is unsuccessful, a second agent, usually of a different mechanism of action, should be
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PMID:Hypertension. 256 99

Hypertension related to renal parenchymal disease is the most common cause of secondary hypertension. Poor control of renal hypertension is associated with an increased risk for progressive atherosclerosis and progressive renal failure. This review discusses the prevalence, significance, and pathophysiology of renal hypertension. Treatment options, both dietary and pharmacologic are reviewed. Special emphasis is given to important pharmacokinetic changes in chronic renal failure. Treatment of hypertensive urgencies and emergencies in this population is also reviewed.
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PMID:Control of hypertension in patients with chronic renal failure. 265 99


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