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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypertension is not simply an acute elevation of arterial pressure during a laboratory experiment. It is the development of a cardiovascular disorder provoking a variety of physiological adaptions brought about by an imbalance of pressor and depressor mechanisms that serve to control arterial pressure at normal levels in the normotensive animal. These pathogenetic mechanisms include hemodynamic, volume, renal parenchymal, sodium, renopressor, catecholamine, neural, hormonal, and even depressor factors. The most common form of the disease is essential hypertension, affecting over 95% of patients with hypertension. Although not the same, the experimental animal model that best mimics essential hypertension is the spontaneously hypertensive rat (SHR). However, to state with certainty that the SHR is a true laboratory duplicate of essential hypertension is inaccurate because the causes of both diseases remain unknown. Both forms are genetically predisposed, naturally occurring, slow but progressive in development, and similar in cardiovascular and hemodynamic adaptions. Both involve arteriolar and venular constriction and myocardial hypertrophy that provide a stable hyperfunctioning adaptation of the heart for a substantial period of time but ultimately lead to cardiac failure, stroke, and other vascular impairment. At best we can conclude that they both represent genetically predisposed disease that involves the disarray of the multifactorial interplay of mechanisms that usually maintain arterial pressure at normal levels.
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PMID:Hemodynamic factors in the pathogenesis and maintenance of hypertension. 708 85

Total exchangeable sodium and blood volume were measured in 126 diabetic patients without renal or heart failure, in 52 patients with essential hypertension and in 99 normal subjects. Both body constituents were judged using the body surface area as the frame of reference. Exchangeable sodium (ExNa) was significantly increased in diabetics as compared to normal subjects (110 vs. 100%), regardless of age, sex or body habitus. ExNa averaged 108% in the 63 diabetics with normal blood pressure, 111% in the 63 hypertensive diabetics and 99% in essential hypertension. Blood volume (BV) was normal or sometimes slightly low in the diabetics with normal or high blood pressure and in essential hypertension. In normal subjects, ExNa or BV were unrelated to age or systolic or diastolic blood pressure. In the diabetic population, ExNa correlated with the systolic blood pressure (r = 0.25; p less than 0.005) but not with the diastolic blood pressure or age; BV was unrelated to blood pressure. The correlation between ExNa and systolic blood pressure was closer in the diabetics with high blood pressure (r = 0.47; p less than 0.001); this relationship could not be explained by a concomitant influence of age or plasma creatinine (rp = 0.34; p less than 0.05). These findings indicate that an increased ExNa associated with a normal circulatory volume is a common abnormality in patients with nonazotemic diabetes mellitus. Excess body sodium may play an important pathogenetic role in the maintenance of diabetes-associated hypertension.
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PMID:Body sodium-blood volume state in nonazotemic diabetes mellitus. 716 75

The cardiac function in Hegglin syndrome (HS; prolonged QT interval and shortened QS2) remains unclear. In order to estimate cardiac function of HS, left ventricular echocardiographic parameters and systolic time intervals (STI) were analyzed, and compared with those of normal subjects (N) (n = 20). Forty-six patients (pts) of HS are constituted of 23 pts with chronic renal failure, 7 with cardiomyopathy, 5 with ischemic heart disease, 5 with essential hypertension, 4 with acquired valvular disease, 1 with effusive pericarditis and 1 with Romano-Ward syndrome. Corrected preejection period (PEPc) and PEP/ET were significantly larger (0.15 +/- 0.02 vs 0.13 +/- 0.01, p less than 0.001; 0.48 +/- 0.13 vs 0.35 +/- 0.04, p less than 0.001, respectively) in HS. Corrected ejection time (ETc) was significantly smaller (0.37 +/- 0.02 vs 0.41 +/- 0.01, p less than 0.001) in HS. Mitral EF slope (DDR), ejection fraction (EF), and mean ventricular circumferential fiber shortening (mVCF) were significantly decreased (58 +/- 29 vs 92 +/- 25, p less than 0.001; 0.52 +/- 0.15 vs 0.62 +/- 0.07; p less than 0.005; 0.98 +/- 0.33 vs 1.18 +/- 0.20; p less than 0.05, respectively) in HS, but cardiac index (C.I.) did not differ. Thus, patients with Hegglin syndrome showed heart failure pattern in STI and hypodynamic cardiac function in echocardiographic parameters, and our data suggest that hypodynamic cardiac function of HS is caused by both lowered pump function and decreased myocardial contractility.
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PMID:[Systolic time intervals and echocardiographic parameters in Hegglin syndrome (author's transl)]. 732 May 60

From at least 1928 until about 1940 essential hypertension was reported to be a rare disease among the population in Kenya and Uganda. Currently, it is 1 of the common causes of heart failure and a major cause of cerebrovascular disease in many hospitals in these 2 nations. Field data in these countries suggest that blood pressure rises during adult life, and essential hypertension occurs in salt-sensitive individuals, when sodium chloride daily intake is excessive. If the intake of potassium chloride is less than that of sodium chloride, and the intake of dietary fiber decreases much, as happens when diets are westernized, these may act as subsidiary risk factors. The East African diets are becoming more and more westernized. The 1st major dietary change involves the addition of much salt to low-salt unprocessed foods. With progressive westernization of diets the foods processed by manufacturers replace homegrown staples. These processed foods contain considerably more sodium, rather less potassium, and much less dietary fiber. While this multiple dietary change takes place, blood pressure levels, previously low and not rising with age, begin to rise during adult life. Essential hypertension, once rare, becomes common in sodium sensitive persons. Diets comparable in many respects to the 1930 Kikuyu diet are suggested to reverse essential hypertension. The therapeutic diet should be of low sodium chloride and should contain much unrefined high fiber high starch foods.
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PMID:From normotension to hypertension in Kenyans and Ugandans 1928-1978. 738 2

The responses in the left ventricular systolic time intervals following digoxin administration (0.5 mg i.v.) were studied in 11 patients with chronic renal failure and hypertension. The control group comprised 11 patients with mild essential hypertension. There were no clinical signs of congestive heart failure in any of the patients. Before digoxin administration total electromechanical systole (QS2), the pre-ejection period (PEP) and the PEP/LVET ratio were greater, while the left ventricular ejection time (LVET) was shorter than in the control group (P < 0.001). In patients with chronic renal failure digoxin administration induced a reduction in QS2, PEP and PEP/LVET ratio and a prolongation of LVET (P < 0.001). These data suggest latent heart failure in the group of patients studied with chronic renal failure. It seems to be advisable to use digitalis preparations in patients with chronic renal failure despite the absence of clinical signs of heart failure.
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PMID:The left ventricular systolic function after digoxin administration in patients with chronic renal failure. 739 45

The effects of oxprenolol on blood pressure levels, pulmonary ventilatory function, myocardial contractility and myocardial oxygen consumption are described in 66 patients with essential hypertension and no clinical evidence of obstructive lung disease of heart failure. Two groups of patients were treated with medication for a total of 16 weeks. Group 1 received oxprenolol and diuretics for the first eight weeks and a placebo plus diuretics for the second eight weeks. Group 2 received the same drugs in reverse order. The results of the study indicate that oxprenolol is an effective antihypertensive drug that does not hamper lung volume capacity or myocardial contractility and markedly reduces myocardial oxygen consumption, although it may cause a mild increase in airway resistance.
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PMID:Effect of oxprenolol on blood pressure, pulmonary ventilatory function and myocardial contractility in hypertensive patients. 739 73

During the history taking and physical examination, several important diseases should be searched for before diagnosing essential hypertension. A critical investigation is repetitive abdominal auscultation for a bruit. In young patients with significant hypertension, coarctation of the aorta must be excluded by clinical examination. Investigations will especially be aimed at uncovering renal artery disease (relatively common) or a phaechromocytoma (relatively rare). The initial assessment must also diagnose associated diseases which will influence the type of therapy chose. Thus asthma and heart failure contraindicate beta-blockers, liver disease contraindicates methyldopa, severe depression contraindicates reserpine, methyldopa and beta-blockade, while diabetes or gout may be precipitated or aggravated by thiazide diuretics.
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PMID:Hypertension in general practice. Part I. Examination and investigation of a patient with hypertension. 744 97

The successful introduction of angiotensin converting enzyme (ACE) inhibitors in the treatment of patients with essential hypertension or heart failure has increased interest in the (patho)physiological role of the renin-angiotensin system (RAS). ACE is not only involved in the formation of angiotensin II from angiotensin I, but also inactivates vasoactive substances such as bradykinin and substance P. Accumulation of these substances during treatment with ACE inhibitors may contribute to both their therapeutic action and certain adverse effects associated with their use, such as cough and angioneurotic oedema. Renin inhibitors offer an alternative approach to inhibit the RAS. The major advantage of these, still experimental, drugs is their high specificity for the RAS since angiotensinogen is the only known substrate of renin. The currently available renin inhibitors are pseudopeptides that are rapidly taken up by the liver and excreted in the bile. Consequently, these drugs are subjected to a considerable first pass effect which limits their oral bioavailability. Additionally, plasma elimination half-life times are short and the duration of action is limited. Despite these shortcomings, single oral or intravenous administration results in a 80 to 90% inhibition of plasma renin activity and a slight reduction in blood pressure in patients with hypertension. The extent of blood pressure reduction is dependent on the patient's salt balance. After 1 week of oral treatment with the renin inhibitor remikiren, the antihypertensive effect was reduced in salt-repleted hypertensive patients. Subsequent intravenous administration of the drug did not further affect blood pressure, indicating that it was not the first pass effect that was limiting the efficacy of remikiren.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical pharmacokinetics and efficacy of renin inhibitors. 758 99

A decrease in the vascular compliance of the large elastic vessels (reduction of their "Windkessel" function) is of decisive importance for the pathogenesis and prognosis of cardiovascular complications such as arteriosclerosis, left ventricular hypertrophy and heart failure. The effect of the antihypertensive calcium antagonist isradipine on the "Windkessel" function of the aorta was measured in terms of the central haemodynamics in ten patients (eight men, two women; mean age 58 +/- 3 years) with essential hypertension (WHO stage I-II) before and 3 months after treatment. The mean arterial blood pressure was obtained invasively from the aortic arch, cardiac output or stroke volume being obtained by the indicator dilution method. The ratio stroke volume/blood pressure amplitude was calculated as a measure of vascular compliance. After 3 months of treatment with isradipine the mean arterial blood pressure fell from 114 +/- 4 to 97 +/- 3 mm Hg (P < 0.01), and total peripheral resistance from 22 +/- 1 to 18 +/- 1 U, P < 0.05), while vascular compliance rose from 1.07 +/- 0.10 to 1.58 +/- 0.10 ml/mm Hg, P < 0.05. The increase in compliance resulted from both the fall in blood pressure per se and the pressure-independent increase in the distensibility of the vessel wall (87 +/- 8% as against 107 +/- 13%, P < 0.05). As the fall in afterload favoured regression in left ventricular hypertrophy and heart failure, this pressure-independent structural and (or) functional change in the great elastic arteries could be decisive for the cardiovascular prognosis of hypertensives.
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PMID:[The compliance of the large elastic arteries after blood pressure-lowering therapy with a calcium antagonist]. 760 Sep 26

Aim of recent experimental and clinical studies has been to evaluate the important role of the renin-angiotensin system in the development of cardiac hypertrophy, of vascular hypertrophy and of left ventricular fibrosis and remodelling in essential hypertension and ischemic heart disease. It has been suggested that ACE-inhibitors are the class of antihypertensive drugs more effective in reducing left ventricular hypertrophy (LVH) in hypertensive patients. The possible mechanisms are, beyond the decrease in blood pressure, the possibility of interfering not only with the renin-angiotensin system activity, but also with the sympathetic nervous system activity as well as with aortic distensibility, all factors that can influence the development of LVH. Vascular changes in essential hypertension are complex and depend not only on the severity of blood pressure levels, but are related to diameter and structure of the vessels and to the presence of other atherosclerosis risk factors. ACE-inhibitors are effective in inducing the regression of structural changes in resistance arterioles and furthermore can increase arterial compliance in large arteries; new studies are undergoing in order to assess the effects of these drugs on atherosclerotic plaque progression/regression. The results of large clinical trials have shown the efficacy of ACE-inhibitors in the treatment of heart failure, in addition, after it has been demonstrated that ACE-inhibitors can influence the structural remodelling process after myocardial infarction, their use has been extended to patients with ischaemic heart disease.
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PMID:[ACE-inhibitors and cardiovascular protection]. 763 57


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