Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In chronic heart failure, neurohumoral mechanisms play an important role in the regulation of cardiac performance directly, by influencing systolic and diastolic function of the myocardium, and indirectly, by modulating pre- and afterload. The important vasoconstrictor, fluid and sodium retaining factors are the renin-angiotensin-aldosterone system, sympathetic nerve activity and vasopressin; the vasodilator, volume and sodium eliminating factors are atrial natriuretic peptide, vasodilator prostaglandins, such as prostacyclin and prostaglandin E2, dopamine, bradykinin and, possibly, endothelium-derived relaxing factor and vasoactive intestinal peptide. There is evidence from experimental and clinical studies that sympathetic nerve activity is stimulated in the early phase of the disease, as is the secretion of atrial natriuretic peptide, which increases in proportion to an increased preload. In early or mild heart failure, atrial natriuretic peptide suppresses the activity of the renin-angiotensin-aldosterone system, may prevent an increase in peripheral vascular resistance and preserves renal blood flow. In more severe heart failure, the renin-angiotensin-aldosterone system is activated, leading to an increase of peripheral and renal vascular resistance and fluid and sodium retention. This is associated with an increased production of vasodilator prostaglandins. In severe heart failure, mostly in connection with hyponatraemia, a non-osmolar inappropriately high secretion of vasopressin can be demonstrated. These findings suggest that early therapeutic intervention to suppress unfavourable neurohumoral mechanisms or to support protective factors, such as atrial natriuretic peptide, may be of particular importance in the treatment of congestive heart failure, delaying progression of the disease, which would improve survival.
 ...
PMID:Hormones in heart failure--regulation and counterregulation. 183 97

The potent diuretic and natriuretic properties of atrial natriuretic factor (ANF) suggest that atrial hormones may participate to the regulation of salt and water excretion under physiological conditions. ANF, via the increase of its intracellular second messenger cGMP, has been recently shown to inhibit the apical sodium channel of the inner medullary collecting tubule (IMCD). In addition, ANF inhibits renin and aldosterone synthesis and antagonizes the antinatriuretic effects of angiotensin II. ANF may also contribute to the excretion of free water by inhibiting both the secretion of vasopressin and its antidiuretic action. ANF appears to play an important physiological role in sodium repleted states, or when the effective plasma volume is increased. On the contrary, when the effective plasma volume is decreased or in sodium depleted states, the natriuretic effect of both endogenous and exogenous ANF is severely blunted. That ANF-resistance may be related to the activation of the renin-angiotensin-aldosterone axis, increased circulating catecholamines, renal sympathetic nerve stimulation, changes in renal hemodynamics or increased degradation of ANF. All these factors could explain the lack of significant natriuretic effect of both endogenous and exogenous ANF in some pathological conditions such as heart failure or liver cirrhosis. ANF may also been concerned in water homeostasis. In addition to the well-known osmoregulatory pathways of water metabolism, we recently found that ANF could be involved in the volume adjustment to acute water intake in normal man.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Atrial natriuretic factor and the endocrine control of electrolyte homeostasis. 183 42

In chronic heart failure, neurohumoral mechanisms play an important role in the regulation of cardiac performance by direct influences on systolic and diastolic function of the myocardium, and indirectly, by modulation of pre- and afterload. Important vasoconstrictor, fluid- and sodium-retaining factors are the renin-angiotensin-aldosterone system, sympathetic nerve activity, and vasopressin; vasodilator, volume, and sodium-eliminating factors are atrial natriuretic peptide, vasodilator prostaglandins like prostacyclin and prostaglandin E2, dopamine, bradykinin, and possibly, endothelial derived relaxing factor (EDRF). There is evidence from experimental and clinical studies that the sympathetic nerve activity is stimulated in the early phase of the disease, as well as is the secretion of atrial natriuretic peptide which increases in relation to a rise in preload. In early or mild heart failure, atrial natriuretic peptide suppresses the activity of the renin-angiotensin-aldosterone system, which may prevent an increase in peripheral vascular resistance and preserve renal blood flow. In more severe heart failure, the renin-angiotensin-aldosterone system is activated, leading to an increase of peripheral and renal vascular resistance and fluid and sodium retention. This is associated with an increased production of vasodilator prostaglandins. In severe heart failure, mostly in connection with hyponatremia, a nonosmolar, inappropriately high secretion of vasopressin can be demonstrated. These findings suggest that early interventions in order to suppress unfavorable neurohumoral mechanisms or to support protective factors like atrial natriuretic peptide may be of particular importance in the treatment of congestive heart failure with the aim of a retardation of the progression of the disease, which would result in an improvement of survival.
 ...
PMID:Role of neuroendocrine mechanisms in the pathogenesis of heart failure. 183 44

Sodium and water retention is characteristic of edematous disorders including cardiac failure, cirrhosis, nephrotic syndrome, and pregnancy. Nonosmotic vasopressin release has been implicated in the water retention of these edematous disorders. The nonosmotic release of vasopressin is consistently associated with activation of the sympathetic nervous and renin-angiotensin-aldosterone systems in both experimental animals and in edematous patients. Moreover, the sympathetic nervous system has been shown to be involved in the nonosmotic release of vasopressin and activation of the renin-angiotensin system. These findings have led to our proposal that body fluid volume regulation involves the dynamic interaction between cardiac output and peripheral arterial resistance. Neither total extracellular fluid volume nor blood volume is a determinant of renal sodium and water excretion. Rather, renal sodium and water retention is initiated by a decrease in effective arterial blood volume (EABV) due to either a fall in cardiac output or peripheral arterial vasodilation. The acute response to a decrease in EABV involves vasoconstriction mediated by angiotensin, sympathetic mediators, and vasopressin. The slower response to restoring EABV involves vasopressin-mediated water retention and aldosterone-mediated sodium retention. The resultant renal vasoconstriction limits the distal tubular delivery of sodium and water, thus maximizing the water-retaining effect of vasopressin and impairing the normal escape from the sodium-retaining effects of aldosterone. The elevated glomerular filtration rate and filtered sodium load in pregnancy allows increased distal sodium and water delivery in spite of a decrease in EABV, thus limiting edema formation during gestation.
 ...
PMID:Unifying hypothesis of sodium and water regulation in health and disease. 193 81

To study the haemodynamic and neurohumoral effects of nisoldipine (2 X 10 mg) vs captopril (3 X 25 mg), 24 patients with heart failure (New York Heart Association class II and III) due to coronary artery disease were treated in a randomized double-blind trial over 3 months. Both drugs were well tolerated. Clinical status was similarly improved in both groups, nisoldipine exerted an additional antiischaemic effect. Nisoldipine lowered the mean arterial pressure and capillary wedge pressure acutely and also after long-term treatment. The increase in cardiac index and stroke volume index, however, which was pronounced after acute administration, was no longer present after 3 months of therapy at rest and was abolished during exercise. Norepinephrine plasma concentration increased after the first dose, plasma renin activity did not change, and aldosterone plasma concentration showed a small insignificant decrease. Urine concentrations of norepinephrine and vasopressin were slightly elevated after the 3-month therapy. After captopril, mean arterial pressure and pulmonary capillary wedge pressure decreased acutely and at follow up. Cardiac index and stroke volume index increased significantly only during exercise at follow-up. Plasma renin activity was significantly elevated and aldosterone plasma concentration only slightly lowered. In contrast to what was seen with nisoldipine, plasma norepinephrine concentration and urine catecholamine and vasopressin concentrations remained unchanged. In conclusion, the pronounced haemodynamic effects seen after the first dose of nisoldipine are mostly abolished after long-term treatment, probably due to neurohumoral counterregulation. The haemodynamic response to captopril is complete only after long-term treatment, without evidence of activation of the neurohumoral systems.
 ...
PMID:Acute and long-term haemodynamic and neurohumoral response to nisoldipine vs captopril in patients with heart failure: a randomized double-blind study. 168 8

Several changes in neuroendocrine activity follow failure of cardiac function to satisfy peripheral requirements and contribute to the clinical syndromes of heart failure. Afferent pathways are poorly understood and triggers are both central and peripheral, involving attenuation of atrial and arterial baroreceptor activity. Efferent sympathetic activity is generally increased with resulting vasoconstriction, but responses are organ-specific and differ among heart, kidney, lung and skeletal muscle. Changes in cardiac sympathetic activity are inadequately understood. Enhanced cardiac norepinephrine spillover contrasts with reduced tissue concentration and impaired activity of synthetic enzymes and neuronal catecholamine uptake. Beta-receptor down-regulation further complicates overall adrenergic responsiveness and the balance between enhancement of contractile function and reduction in arrhythmia threshold. Activation of the renin-angiotensin system is potentiated by the sympathetic nervous system and may contribute to vasoconstrictor hyporesponsiveness. Angiotensin II may in turn facilitate the central and peripheral effects of sympathetic activation and the release of vasopressin from the pituitary. Our understanding of the role of vasodilator peptides in heart failure remains rudimentary. It is likely that vasoconstrictor neuroendocrine response adversely influences optimal cardiac function in heart failure and may promote arrhythmogenesis. The neuroendocrine response in individual organs, however, requires intensive study.
 ...
PMID:Neuroendocrine activation in congestive heart failure. 202 Nov 17

In experiments with isolated animal hearts it has been ascertained that free hemoglobin, lactic acids, catecholamines, vasopressin and acetylcholine at the concentrations they appear in patients' blood during open heart surgeries can produce cardiodepressive effects and cause acute heart failure. Cardiac reperfusion with a solution containing 20% less sodium, potassium, calcium, magnesium and hydrogen ions leads to severe heart failure: lower osmotic capacity and/or concurrent smaller Na+ and H+ concentrations were responsible for myocardial contractility disturbances.
 ...
PMID:[Causes of disorders of the contractile function of the heart after cardioplegia]. 204 40

Since Shumway carried out the first successful heart-lung transplant (HLT) in Stanford in 1981, HLT has become a new therapeutic means for patients with end-stage pulmonary disease or arterial hypertension. However, it is still rarely carried out because of a lack of donors and the complexity of the surgery and postoperative course. This review described the criteria for proper donor and recipient selection, as well as the anaesthetic and postoperative management of HLT patients at Marie Lannelongue Hospital. The lack of suitable organ grafts results, at least in part, from improper donor management. Pulmonary oedema by fluid overloading and excessive haemodilution should be carefully prevented. Low doses of catecholamines and vasopressin maintain circulatory stability and convenient organ function. The indications for HLT (primary pulmonary hypertension, Eisenmenger's complex, and end-stage bronchopulmonary disease) are all characterized by severe pulmonary hypertension, hypoxaemia and cardiac failure. Careful anaesthetic induction is required to avoid circulatory collapse. Cardiopulmonary bypass (CPB) should be started early, so that mediastinal dissection may be carried out in satisfactory haemodynamic conditions. After unclamping the aorta, circulatory support with fluid and catecholamine infusion is often required. High inspired oxygen fraction and end-expiratory positive pressure may be required because of reperfusion pulmonary oedema. Blood transfusion is often needed as there are major blood losses due to dissection of the posterior mediastinum during CPB. Postoperative catecholamine administration is prolonged over several days. Negative fluid balance is often necessary to reduce pulmonary oedema. Improvement in surgical technique, early extubation, and late prescription of steroids have reduced the incidence of tracheal complications. Acute renal failure often occurs as a result of prolonged CPB, hypovolaemia, drug nephrotoxicity and sepsis. Bacterial complications (pneumonia, mediastinitis) are the main causes of early death. After the 15th postoperative day, opportunistic infections and allograft rejection are the main complications. Since 1981, major advances in HLT recipient management resulted in improved survival rates (70-80% at 1 year, and 60-70% at 2 years for the best teams). Despite the complexity of management, and the longterm threat of obliterative bronchiolitis, HLT is, at present time, the only possibility for these young patients to recover a normal quality of life.
 ...
PMID:[Anesthesia and intensive care for heart-lung transplantation]. 205 32

Conditions like heart failure that augment the activity of neurohumoral mechanisms i.e. the renin-angiotensin systems, sympathetic nerve activity and vasopressin secretion are commonly associated with a decreased effective blood volume and a reduced renal perfusion. This leads to an increased dependence of renal hemodynamics on endogenous renal prostaglandin synthesis as a vasodilator and natriuretic counter-regulating system. We investigated the role of prostaglandins in renal functional control in an experimental setting of congestive heart failure by chronic inhibition of cyclooxygenase by indomethacin. In chronic moderate heart failure plasma levels of prostaglandin E2 and prostacyclin were unchanged whereas the urinary excretion of prostaglandin E2 was significantly increased, indicating an augmented synthesis within the kidney (Figures 1 to 3). After inhibition of prostaglandin synthesis we observed a profound increase of renal vascular resistance associated with a reduction of effective renal plasma flow and renal blood flow. This was mainly due to a constriction of the vas afferens of the glomerulum. This led to an impairment of renal function indicated by an increase of serum creatinine and blood urea nitrogen associated with a reduction of urinary flow and fluid retention (Figures 4 and 5). We also studied in a randomized, double-blind, placebo-controlled, parallel-group trial in 40 patients with congestive heart failure effects of acetylsalicylic acid (500 mg t.i.d.) on renal functional parameters. In patients with normal sodium intake acetylsalicylic acid reduced urinary prostaglandin E2 concentration by 37% which led to a reduction of daily urinary sodium excretion by 29% in comparison to placebo (Figure 6). These results clearly show the importance of vasodilator prostaglandins in the regulation of kidney function in heart failure where inhibition of cyclooxygenase results in profound deterioration of renal perfusion and kidney function and retention of fluid and sodium.
 ...
PMID:[Role of prostaglandins in regulation of kidney function in heart failure]. 206 53

Sodium and water retention is characteristic of edematous disorders including cardiac failure, cirrhosis, nephrotic syndrome, and pregnancy. In recent years, the use of a sensitive radioimmunoassay for plasma vasopressin has implicated the role of nonosmotic vasopressin release in the water retention of these edematous disorders. In experimental studies and studies in man, it has been found that the nonosmotic release of vasopressin is consistently associated with the activation of the sympathetic nervous and renin-angiotensin-aldosterone systems. Moreover, the sympathetic nervous system has been shown to be involved in the nonosmotic release of vasopressin (carotid and aortic baroreceptors) and in the activation of the renin-angiotensin system (renal beta-adrenergic receptors). These findings have led to our proposal that body fluid volume regulation involves the dynamic interaction between cardiac output and peripheral arterial resistance. In this context, neither total extracellular-fluid (ECF) volume nor blood volume are determinants of renal sodium and water excretion. Rather, renal sodium and water retention is initiated by either a fall in cardiac output (e.g. ECF volume depletion, low-output cardiac failure, pericardial tamponade, or hypovolemic nephrotic syndrome) or peripheral arterial vasodilation (e.g. high-output cardiac failure, cirrhosis, pregnancy, sepsis, arteriovenous fistulae, and pharmacologic vasodilators). With a decrease in effective arterial blood volume (EABV). initiated by either a fall in cardiac output or peripheral arterial vasodilation, the acute response involves vasoconstriction mediated by angiotensin, sympathetic mediators, and vasopressin. The slower response to restoring EABV involves vasopressin-mediated water retention and aldosterone-mediated sodium retention. The renal vasoconstriction which accompanies those states that decrease EABV, by either decreasing cardiac output or causing peripheral arterial vasodilation.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:A unifying hypothesis of sodium and water regulation in health and disease. 210 96


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>