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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pharmacokinetics, clinical efficacy, and adverse effects of three calcium-channel blocking agents--verapamil, nifedipine, and diltiazem--are reviewed. Verapamil, nifedipine, and diltiazem are absorbed well after oral dosing, but absolute bioavailability of each is reduced substantially by a first-pass effect. Each drug is metabolized extensively (verapamil and diltiazem to moderately active metabolites) by the liver. A substantial percentage of each drug is bound to plasma proteins, but the binding is of clinical importance only for nifedipine (92--98% protein bound). Intravenous verapamil has become the agent of first choice for treatment of acute paroxysmal supraventricular tachycardia (PSVT); use of chronic oral verapamil therapy for prophylaxis remains controversial. Verapamil and diltiazem have been evaluated with mixed results for atrial flutter and fibrillation. For treatment of myocardial ischemia, calcium-channel blockers may be of some value (possibly in combination with nitrates of B blockers). All three agents have been studied in patients with exertional angina with good results. Calcium-channel blockers appear to be equal with nitrates for treatment of variant angina. Patients with hypertropic cardiomyopathy have been treated with verapamil and nifedipine with promising results. Nifedipine has been effective for treatment of essential hypertension. Adverse effects of calcium-channel blockers have been relatively minor or infrequent. Diltiazem overall has the best side-effect profile, with adverse effects causing discontinuation of therapy in about 2--10% of patients; verapamil in intermediate (8--10%) and nifedipine the worst (17%) in this respect. The most common side effects generally are fatigue, headache, dizziness, skin rash, and peripheral edema. While they generally should be reserved for patients in whom more conventional therapy has failed (except those with PSVT), calcium-channel blockers appear to have a valid role as reserve agents for exertional and variant angina, cardiomyopathy, and hypertension.
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PMID:Update on calcium-channel blocking agents. 635 66

Studies with school aged children of several communities of the United States have indicated that between one and two percent of them should be considered hypertensive. These findings contradict previous statements of a very rare incidence of hypertension in childhood. Some studies show that children of Black and Hispanic American ancestry, especially females, have a higher incidence of hypertension. The highest incidence of hypertensive children was related to a history of familial hypertension and obesity. In children less than three years of age and in infants, hypertension is less frequent. A disease of the urinary apparatus (nephropathy) or of the cardiovascular system (aorta coarctation) can often be identified as the primary cause of the hypertension. Less frequent is hypertension sustained by adrenal cortical dysfunction or a neoplasm of the adrenal medulla. Hypertensive crisis also frequently develops in children after thermal injury or renal transplant. In children, the use of antihypertensive drugs should be reserved for cases where the disease is very severe. Effective regulation of dietary and hygienic habits should be recommended, particularly for those cases of "mild" or "borderline" essential hypertension.
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PMID:Considerations of the renin-angiotensin aldosterone system in the pathogenesis of hypertension in infancy. 675 76

The effectivity of subendocardial perfusion was investigated in 266 probands aged 40-68 years (112 patients with ischaemic heart disease, 116 patients with essential hypertension, and 38 practically healthy persons) by a noninvasive technique - the myocardial vitality index (MVI) or the quotient of the diastolic and systolic tension-time indexes (DTTI/STTI). The close and statistically significant correlation was found between the MVI, findings of selective coronarography, and total physical performance (exercise tolerance threshold) in per cent of the maximal oxygen consumption (MOC) adequate to the given subject's age, sex, and body mass. Attention is drawn to the diagnostic potential of the novel mode of a rapid assessment of the expected exercise tolerance threshold in per cent of the admissible MOC, determined by the magnitude of the coronary reserved of energy output (in kcal/min or kJ/min), and to the possibilities of predicting the maximal admissible heart rate during exercise on the basis of the myocardial oxygen supply/consumption quotient during a state of relative muscular rest, reflecting the MVI.
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PMID:The diagnostic significance of the correlation between the effectiveness of subendocardial perfusion and the energy output compatible with the coronary reserve. 706 62

Patients with mild to moderate hypertension require only a simple schedule of investigations, especially if there is a history of stroke or hypertension in first degree relatives. Tests are necessary to profile other cardiovascular risk factors and to detect target organ damage with only limited screening for secondary hypertension. Careful history, physical examination, repeated blood pressure measurements over months and measurements of body mass index, random cholesterol, routine blood chemistry and urinalysis using impregnated paper strips are all that are required. More detailed investigations can be reserved for special groups such as those with peripheral vascular disease or abnormal renal function before or after treatment with angiotensin converting enzyme inhibitors or significant proteinuria or hypokalaemia. Patients with essential hypertension who are smokers with lipid abnormalities may go on to develop superimposed renovascular disease. Severe hypertension at any age and especially if there is a reliable negative family history also merits special consideration. Resistance to antihypertensive treatment is more often due to non-compliance or non-steroidal anti-inflammatory drug use or alcohol abuse than to underlying secondary causes.
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PMID:Hypertension: investigation, assessment and diagnosis. 820 68

The differences of arrhythmias among distinct left ventricular geometric patterns in the patients with essential hypertension were studied. 179 patients with essential hypertension received 24 h dynamic ECG recording, ambulatory blood pressure monitoring, echocardiography examination, etc. According to the examinations, left ventricular geometric patterns and arrhythmias were identified. The comparison of morbidity of arrhythmias between the left ventricular remodeling group and the normal geometric pattern group was performed. The multiple stepwise regression analysis was carried out to identify the independent determinants of arrhythmias. After these predictors were controlled or adjusted, the severity of arrhythmias among different left ventricular geometric patterns was compared. It was found that the morbidity of atrial arrhythmia, ventricular arrhythmia and complex ventricular arrhythmias in the left ventricular remodeling group was significantly higher than in the normal geometric pattern group respectively. There were many independent factors influencing on arrhythmias in essential hypertension. Of all these factors, some indices of left ventricular anatomic structure, grade of hypertension, left atrial inner dimension, E/A, diastolic blood pressure load value at night and day average heart rate and so on were very important. After the above-mentioned factors were adjusted, the differences of the orders of arrhythmias between partial geometric patterns were reserved, which resulted from the differences of the geometric patterns. Many factors contributed to arrhythmias of essential hypertension, such as grade of hypertension, LVMI, LA, PWT and so on. The severity of arrhythmias was different in different left ventricular geometric patterns.
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PMID:Comparison of arrhythmias among different left ventricular geometric patterns in essential hypertension. 1152 33

Brain natriuretic peptide (BNP) is predominantly a cardiac ventricular hormone that promotes natriuresis and diuresis, inhibits the renin-angiotensin-aldosterone axis, and is a vasodilator. Plasma BNP levels are raised in essential hypertension, and more so in left ventricular (LV) hypertrophy and heart failure. Plasma BNP levels are also elevated in ischemic heart disease. Attempts have been made to use plasma BNP levels as a marker of LV dysfunction, but these have shown that plasma BNP levels are probably not sensitive enough to replace echocardiography in the diagnosis of LV dysfunction. Pericardial BNP or N-BNP may be more suitable markers of LV dysfunction. Plasma BNP levels are also elevated in right ventricular dysfunction, pregnancy-induced hypertension, aortic stenosis, age, subarachnoid hemorrhage, cardiac allograft rejection and cavopulmonary connection, and BNP may have an important pathophysiological role in some or all of these conditions. Clinical trials have demonstrated the natriuretic, diuretic and vasodilator effects, as well as inhibitory effects on renin and aldosterone of infused synthetic human BNP (nesiritide) in healthy humans. BNP infusion improves LV function in patients with congestive heart failure via a vasodilating and a prominent natriuretic effect. BNP infusion is useful for the treatment of decompensated congestive heart failure requiring hospitalization. The clinical potential of BNP is limited as it is a peptide and requires infusion. Drugs that modify the effects of BNP are furthering our understanding of the pathophysiological role and clinical potential of BNP. Increasing the effects of BNP may be a useful therapeutic approach in heart failure involving LV dysfunction. The levels of plasma BNP are increased by beta-blockers, cardiac glycosides and vasopeptidase inhibitors, and this may contribute to the usefulness of these agents in heart failure. (c) 2001 Prous Science. All rights reserved.
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PMID:Brain natriuretic peptide: Disease marker or more in cardiovascular medicine? 1275 Jul 64

Essential hypertension accounts for 95% of all cases of hypertension. A small number of patients (between 2% and 5%) have a reversible disease as the cause for raised blood pressure. Unilateral and bilateral renal artery stenosis may be responsible for secondary hypertension. Diagnosis and treatment of renal artery stenosis are of a great importance. Revascularization of ischemic kidney may correct blood pressure control and preserve renal function. Much data suggest close pathophysiological relation between renal artery stenosis, ischemic nephropathy and development of hypertension. However, it should be stressed that not every renal artery stenosis leads to hypertension and ischemic nephropathy. Therefore diagnosis of renal artery stenosis in hypertensive patient is not always equivalent with renovascular hypertension. The true prevalence of renal artery stenosis is unknown. In unselected population it accounts for less than 1% of hypertensive patients. Renovascular etiology of hypertension may be suggested by abrupt onset of hypertension, resistant and malignant hypertension or recurrent pulmonary edema of unknown etiology. Physical examination may reveal bruits over major vessels, including the abdominal aorta and renal arteries. The principle aim of the renal artery stenosis investigation is to confirm presence and size of vessel obstruction and its association with hypertension. Typical evaluation is based on imaging techniques and physiological studies. Former include: doppler duplex ultrasonography, conventional angiography, intraarterial and intravenous digital subtraction angiography, computed axial tomography, magnetic resonance angiography and intravascular ultrasonography. Functional studies are occasionally used. These are renal scintigraphy, evaluation of plasma renin activity in renal veins and evaluation of plasma rennin activity after ACE inhibition. Treatment of patients with renal artery stenosis and hypertension should restore vessel patency and inhibit its occlusion. Revascularization should elicit an improvement in or normalization of blood pressure control and renal function. Therapeutic approach include percutaneous renal artery angioplasty (PTRA), with or without stenting, revascularization by surgery and pharmacotherapy. PTRA is currently the first choice option. In general, it is simpler and similarly effective as surgical reconstruction. In some cases PTRA is completed with stent placement. It prevents immediate recoil but does not completely eliminate restenosis of revascularized artery. Surgical bypass is currently reserved for patients in whom PTRA and stenting fail and in patients with extensive atherosclerotic lesions. Patients with renal artery stenosis and hypertension should be provided with pharmacological treatment according to current recommendations. Specific procedures to limit associated risk factors of atherosclerosis should also be introduced.
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PMID:[Renovascular hypertension: is it only the top of the iceberg?]. 1497 69

Hypothalamic magnocellular neurons secrete vasopressin into the systemic circulation to maintain blood pressure by increasing renal water reabsorption and by vasoconstriction. When blood pressure rises, baroreflex activation normally inhibits vasopressin neurons via activation of GABAergic inputs. However, plasma vasopressin levels are paradoxically elevated in several models of hypertension and in some patients with essential hypertension, despite increased blood pressure. We have previously shown that vasopressin neuron activity is increased early in the development of moderate angiotensin II-dependent hypertension via blunted baroreflex inhibition of vasopressin neurons. Here, we show that antagonism of vasopressin-induced vasoconstriction slows the development of hypertension and that local administration of a GABAA receptor antagonist inhibits vasopressin neurons during, but not before, the onset of hypertension. Taken together, our data suggest that vasopressin exacerbates the increase in blood pressure evident early in the development hypertension and that blunted baroreflex inhibition of vasopressin neurons is underpinned by an excitatory shift in their response to endogenous GABA signalling. This article is protected by copyright. All rights reserved.
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PMID:A switch from GABA inhibition to excitation of vasopressin neurons exacerbates the development angiotensin II-dependent hypertension. 2922 49