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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe the hemodynamic and neurohormonal data during ventricular assistance device system support as a bridge to heart transplantation of one patient, 30 years old, with heart failure due to Chagas' heart disease in functional class IV. We determined the pressures in mmHg of right atrium (RA), pulmonary artery pressure (PAP), pulmonary wedge pressure (WEDGE), arterial blood pressure (AP), and the cardiac output (CO) in l/min. In addition, the blood levels of norepinephrine (Ne), renin (Re), epinephrine (Ep), lactate and the mixed venous oxygen pressure (pVO2) were determined. The CO increased from 2.14 to 3.9-4.2 l/min, the AD decreased from 26mmHg to 8mmHg, the MPAP reduced from 38mmHg to 14-24mmHg, the WEDGE reduced from 25 to 4mmHg and the AP become normal. The Ne reduced from 1927pg/ml to 983pg/ml, the lactate reduced from 99mg/dl to 22mg/dl and the pVO2 increased from 28mmHg to 43mmHg. The EP remained between 81pg/ml and 129pg/ml, the renin activity remained between 113ng/ml/hr and 136ng/ml/hr. Thus, during the ventricular assistance device system support there was a improvement in hemodynamic and neurohormonal conditions. The patient underwent successful heart transplantation.
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PMID:[Hemodynamic and neurohormonal profile during assisted circulation with heterotopic artificial ventricle followed by heart transplantation]. 801 Aug 94

In the progression from myocardial hypertrophy to heart failure, abnormalities in the interstitial space of the heart seem to play a critical role. The formation of an extracellular oedema and the alterations in coronary subendocardial perfusion are associated with the development of interstitial fibrosis. Cardiac experimental studies documented the presence of augmented interstitial fluid volume and pressure and a subsequent remodelling of the fibrillar network of the extracellular space of the myocardium during the phases of the cardiovascular response to a sudden overload. Variations of the Starling's forces balance caused by enhanced endothelial permeability or due to an impairment of cardiac lymphatic drainage may contribute to the development of an acute heart failure. During stable hyperfunction, the organization of a chronic oedema should account for interstitial changes in the hypertrophic myocardium. Reactive fibrosis seems to be under hormonal control. The activation of the renin-angiotensin-aldosterone system is responsible for interfascicular and intercellular accumulation of fibrillar collagen within the cardiac interstitium. Perivascular fibrosis in the subendocardium may impair intramyocardial distribution of coronary flow. When an inadequate hypertrophy occurs, because of an elevation in ventricular wall stress, myocardial oxygen consumption rises and this may lead to the exhaustion of coronary blood flow reserve in the subendocardial layers. This underperfusion may be responsible for the development of myocardial ischemia. Coronary hemodynamic changes in the microcirculation as those prompted by interstitial alterations may contribute to the onset of myocyte necrosis and to the formation of restorative fibrosis. The progressive mechanical overload of the spared hypertrophied myocytes could explain the initiation of a positive feedback mechanism which perpetuates endomyocardial perfusion impairment, interstitial oedema and remodelling, finally, causing myocyte deaths and fibrous tissue proliferation. These structural alterations and their pathophysiological counterparts appear to be closely related to the evolution from compensatory hypertrophy to chronic myocardial failure in hypertrophic heart disease.
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PMID:[From myocardial hypertrophy to heart failure: role of the interstitium]. 802 50

H and K ions play central roles in prorenin processing and secretion, and prorenin is abnormally expressed in H and K disorders. At the surface membrane of juxtaglomerular (JG) cells, K is sensed and regulated by K channels (coupled to Cl channels and activated by excess Ca), Na-K-adenosinetriphosphatase, and a KCl/H exchange transporter (regulated by Ca). In JG cell granular membrane, K flux is regulated by K channels and a KCl/H exchange transporter (activated by Ca). H channels and a H pump reside in the granular membrane, which maintain H concentration in the granular matrix at least two orders of magnitude greater than in cytosol. The H pump may also be responsible for maintaining the acidic matrix required for maximal prorenin processing to renin by prohormone convertase for human renin (PCren), the prorenin convertase. These molecules form the core of a chemiosmotic system, which appears to regulate both prorenin processing and renin secretion. Renin secretion and prorenin processing appear to be of more than causal significance in clinical disorders characterized by chemiosmotic imbalance. A critical review of the literature supports the following general conclusions. First, hyperrenin state defines the initial phase in the pathogenesis of heart disease, diabetes mellitus, and hypertension. Second, low-renin syndrome defines the transition-to-establish phase in the pathogenesis of heart disease, diabetes mellitus, and hypertension in which the key feature is renin secretory hyporesponsivity. Third, renin disorders are usually associated with other endocrine disorders (polyendocrinopathies types I, II, and III), suggesting that renin may be an important molecule in the processing of chemiosmotic forces. The key chemiosmotic molecules (K and H) are also important in the processing and export of most (if not all) hormones. Thus, by regulating K and H homeostasis, renin may regulate the endocrine system.
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PMID:Hydrogen and potassium regulation of (pro)renin processing and secretion. 804 49

Renal artery stenotic disease is the most common form of surgically correctable hypertension. Occlusive lesions of the renal artery are categorized as: arteriosclerotic, fibrodysplastic (intimal fibroplasia, medial fibrodysplasia, perimedial dysplasia) and developmental. The incidence of stroke, heart disease and renal failure has been reduced with contemporary drug management of hypertensive vascular disease, but similar salutary outcomes have not accompanied the medical treatment of renin-mediated renovascular hypertension. Selection of patients for operation implies documentation that a renal artery stenosis is of functional importance. Advances in the surgical management of renovascular hypertension have evolved over the past 50 years, such that carefully performed reconstructions benefit 85-95% of properly selected patients.
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PMID:The evolution of surgery for renovascular occlusive disease. 804 46

The renin-angiotensin system (RAS) is known as a system which constricts vessels and enhances renal retention of sodium and water to raise the blood pressure. Recent studies have shown that the RAS is related to pathogenesis of cardiovascular diseases: 1) angiotensin-converting enzyme (ACE) inhibitor has been known to regress the cardiac hypertrophy, 2) high renin activity before treatment of hypertension has been reported to be one of the risk factors of myocardial infarction, 3) and there was a study that the gene expression of ACE was related to the susceptibility to myocardial infarction. Recently, in addition to the circulating RAS, the existence of the tissue RAS in various organs has been demonstrated. However, the existence of the tissue RAS in the human heart and its pathophysiological significance have not been fully investigated. To confirm the existence of the tissue RAS in the human heart, and clarify its pathophysiological role, we focused on the important elements of the system, renin and ACE, and studied the presence of renin and ACE mRNAs and their proteins in the human autopsied hearts. Samples were taken from the organs from 15 cases without heart disease. Renin mRNA was examined using reverse transcription-polymerase chain reaction. In all of 15 cases, renin mRNA was detected in the right atrium, but not in the left ventricle. Renin protein was found both in the right atrium and the left ventricle by Western blot. In addition to renin, ACE mRNA was also detected both in the right atrium and left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Synthesis of renin and angiotensin-converting enzyme in human heart]. 811 8

The renin-angiotensin system has important pathophysiologic implications in the development of congestive heart failure. The activity of the renin-angiotensin system early in the course of heart disease and heart failure in dogs was evaluated by measuring the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) in 18 Cavalier King Charles Spaniels with asymptomatic or mildly symptomatic mitral valvular insufficiency, and in 18 healthy Cavalier King Charles Spaniels. All dogs were unmedicated and had no other diseases. The PRA was high in the dogs with mitral valvular insufficiency (median 3.44 ng/mL/h, interquartile interval 2.59 to 8.66 ng/mL/h) compared with the controls (median 2.51 ng/mL/h, interquartile interval 1.44 to 3.58 ng/mL/h). The PAC was also higher in the dogs with mitral insufficiency (median 53 pg/mL, interquartile interval 33 to 138 pg/mL) than in the control group (median 27 pg/mL, interquartile interval 11.5 to 54 pg/mL). However, there was considerable overlap between the 2 groups in both PRA and PAC. It was concluded from these data that there is early activation of the renin-angiotensin system in some Cavalier King Charles Spaniels with mitral valvular insufficiency. Further prospective studies are needed to determine if early intervention with angiotensin-converting enzyme inhibitors will be valuable in this group of patients.
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PMID:Activation of the renin-angiotensin system in dogs with asymptomatic and mildly symptomatic mitral valvular insufficiency. 853 Nov 78

Atrial natriuretic factor (ANF) is a peptide hormone secreted by the atria in response to increased transmural pressure. This peptide is the first of a series of natriuretic hormones which also includes brain natriuretic peptide (BNP). It is destroyed mainly by an ubiquitous enzyme, neutral endopeptidase (NEP). Its main actions are vasodilatation and natriuresis. It is the main physiological agonist of the renin/angiotensin/aldosterone system. In elderly subjects free of cardiovascular disease, baseline concentrations are higher than in younger subjects. In patients with congestive heart disease (CHD), the level of ANF rises due to permanent increased filling pressures. Both atrial and ventricular secretion increase ANF levels which loose their day/night rhythm. ANF is a risk factor independent of mortality, rhythm disorders and acute heart failure in patients with heart failure. BNP is also raised in CHD. There is an inverse correlation between concentration and severity of left ventricule dysfunction. There has been little work on ANF in elderly subjects with CHD. ANF is elevated in these patients and is an independent risk factor for cardiac decompensation. In addition, in very elderly subjects where the diagnosis of CHD is difficult and echocardiography not always possible, assay of BNP could be an interesting diagnostic tool. Currently work on therapeutic possibilities (administration of exogenous ANF, combinations with NEP inhibitor/conversion enzyme inhibitor, ANF/diuretics) have revealed certain problems (short half life of ANF, transient effects, non-specific activity of NEP). The usefulness of ANF and BNP in heart failure in elderly subjects will undoubtedly lie in its capacity to mark disease severity and as a diagnostic tool, particularly in case of acute dyspnoea.
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PMID:[Atrial natriuretic factor and brain natriuretic peptide. Variations in elderly subjects with heart failure]. 854 37

To understand the significance of the tissue renin-angiotensin system in the heart, we examined the expression of renin and angiotensin-converting enzyme (ACE) in autopsied human hearts. Samples were taken from organs obtained at autopsy from 15 patients without heart disease and 3 patients with heart disease (old myocardial infarctions, acute myocardial infarctions, and hypertrophic cardiomyopathy). We examined the expression of renin and ACE mRNA by using the reverse transcription-polymerase chain reaction (RT-PCR). RT-PCR showed the expression of renin in the right atria in all patients. However, expression of renin mRNA in the left ventricles was not found in any of the 15 hearts without heart disease. In contrast, renin mRNA was detected in the left ventricles in hearts with heart disease. ACE mRNA was detected in both the atria and the ventricles in normal hearts, and its expression did not alter in diseased hearts. These findings suggest that renin mRNA is expressed mainly in the right atria in normal hearts, but that its expression in the left ventricle can be activated in some pathological conditions.
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PMID:Expression of renin and angiotensin-converting enzyme in human hearts. 865 65

Considerable progress has been made in the medical treatment of chronic heart failure. A large number of patients with NYHA class II and III heart disease can be improved to class I and II. Treatment is maintained on an outpatient basis in order to prevent episodes of acute failure, while avoiding the adverse effects of drugs at high doses or in combination. Diuretics are still the drug class most frequently prescribed, especially loop diuretics (furosemide) which have the advantage of being able to be used in patients with renal failure. Aldosterone antagonists have the pathophysiological value of reducing the development of myocardial fibrosis. Digitalis alkaloids have a positive inotropic effect, which is even observed in the presence of sinus rhythm and which is associated with slowing of the heart rate in tachyarrhythmias. Angiotensin converting enzyme inhibitors are among the most recently used drugs. They decrease the left ventricular post-load and prevent activation of the renin-angiotensin-aldosterone system. Phosphodiesterase inhibitors cannot be administered orally in the long-term and are therefore not suitable for outpatient treatment. However, they are very effective by intravenous injection during the acute phase of heart failure and cardiogenic shock in hospital.
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PMID:[Ambulatory treatment of chronic cardiac insufficiency]. 866

Plasma renin activity (PRA), angiotensin II (ATII), aldosterone (ALD) and atrial natriuretic factor (ANF) were determined in 30 patients with high altitude myocardial hypoxidosis (HAMH) with radioimmunoassay and the data were compared with those of 40 healthy subjects and 26 patients with high altitude chronic cardiopathy (HACC). All of them have been in Lasa, a place with an altitude of 3,658 meter, for a long time. The results showed that PRA and plasma ATII increased significantly (P < 0.05-0.01) and plasma ANF decreased significantly (P < 0.01) in patients with HACC and were higher than those in the control. It is suggested that disturbance of these biologically active substances might play a role in the development of HAMH.
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PMID:[The significance of changes in plasma renin angiotensin aldosterone system and atrial natriuretic factor in patients with high altitude myocardial hypoxidosis]. 873 58


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