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

A novel series of pyrimidine derivatives was synthesized and evaluated for positive inotropic activity. Inotropic and chronotropic effects were determined in vitro in cat papillary muscle and right atrium, respectively. Selected compounds were then evaluated in vivo in a dog heart failure model. Changes in ventricular dP/dt, heart rate, and blood pressure were monitored. Several of these agents produced relatively minor changes in heart rate. This class of agents demonstrated a varying degree of vasodilator effects concomitant with increases in ventricular contractility. The most potent analogues, 9, 48, and 49, were evaluated orally in conscious dogs with implanted Konisberg pressure transducers, and their effect on left ventricular dP/dt was compared with that of milrinone. Mechanistically, the agents of this novel class appear not to mediate their effect via beta-receptors or inhibition of Na+/K+-ATPase. A major component of their inotropic effect is mediated by the inhibition of cardiac phosphodiesterase (PDE)-Fr. III. This was clearly demonstrated by 9, 48, and 49. Compound 48 was found to be the most potent inhibitor of PDE-Fr. III from among the compounds tested in this assay.
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PMID:Chemistry and positive inotropic effect of pelrinone and related derivatives. A novel class of 2-methylpyrimidones as inotropic agents. 283 2

New method for measuring plasma and urinary Na-K-ATPase inhibitor (ATPI) was developed. Plasma and urine were extracted with reversed phase cartridge column and sample was reconstituted by assay buffer. Na-K-ATPase inhibitory activity of sample was monitored by continuously recording the absorbance of NADH at 340 nm, which coupled to the dephosphorylation of ATP. Ouabain was used for standards of Na-K-ATPase inhibition and this standard showed good linearity ranged 5-100 nmol/ml. Using this new method, P-ATPI and U-ATPI were quantitatively evaluated and paradoxical Na-K-ATPase stimulating phenomenon which observed in conventional method (Hamlyn et al) was diminished. Adopting of this new method for measuring plasma(P-) and urinary(U-)ATPI, and radioimmunoassay for P- and U-digitalis-like substance(DLS)--using crossreactivity to anti digoxin antibody--, these substances were estimated in patients with essential hypertension (EHT), chronic heart failure(CHF), primary and idiopathic hyperaldosteronism(HA), hyperthyroidism(BA) and chronic renal failure(CRF). In EHT, U-DLS, P-DLS, U-ATPI, P-ATPI were significantly higher than those of control(C). In CHF and BA, U-DLS and -ATPI were also significantly higher than those of C. In HA, U-ATPI, DLS distributed in wide range, and a few patients showed high levels of U-DLS and -ATPI. In CRF, P-DLS and -ATPI levels were significantly higher than those of C in prehemodialytic state but P-ATPI was significantly decreased after hemodialysis. From these results it is suggested that 1) DLS and ATPI might contribute to the etiology of hypertension. 2) Volume expansion stimulates the secretion of DLS and ATPI. 3) Stimulatory effect of volume expansion and inhibitory effect of mineralocorticoid may be responsible for wide distribution of these factors in HA. 4) DLS and ATPI are not the same substances.
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PMID:[Endogenous digitalis-like substance and Na-K-ATPase inhibitor in cardiovascular and renal disease]. 283 14

Maternal endoxin (digoxinlike substance) is proposed as arising in the fetal area of the fetal adrenal cortex. Its function may be to sensitize the uterus for labor, much as does cortisol in the sheep fetus. Because endoxin is a sodium-potassium-adenosine triphosphatase inhibitor, however, it may also induce maternal vasoconstriction. On our service, normal pregnant women have detectable endoxin after 35 weeks with increasing amounts at term. Specimens of cord blood often have "digoxin" in the therapeutic range. We find that about 40% of women in premature labor and 65% of pregnant women with hypertension have elevated levels of serum endoxin. Postdate gravid women sometimes have very low endoxin levels. Pregnant women with complications and elevated digoxin (endoxin) levels could have specific antidigoxin therapy if endoxin proves to be a modulator of their symptoms. Digoxinlike substances are also sometimes elevated in ill nonpregnant persons, such as those with renal, liver, or heart failure, or hypertension.
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PMID:Fetal endoxins and complications of pregnancy. 284 75

To elucidate further the possible role of atrial natriuretic peptide (ANP) and hypothetical natriuretic hormone (NH) in volume and BP regulation in chronic renal failure (CRF) we measured plasma ANP, digitalis-like substances (DLS) and Na+-K+-ATPase activity (using 86Rb influx into RBC) in 9 patients with CRF before and after hemodialysis. Volume expansion between consecutive dialyses led in all patients to the elevation of plasma ANP (83.4 +/- 14.2 pmol/l) reaching in some overhydrated subjects and/or patients with concomitant cardiac insufficiency concentration greater than 150 pmol/l. Reduced 86Rb influx into RBC before hemodialysis (37.7 +/- 4.9% of controls) was accompanied by higher DLS concentrations (201 +/- 32 pmol/l). Ultrafiltration during hemodialysis with ECFV reduction lowered both ANP and DLS concentrations to 28.1 +/- 9.4 pmol/l and to 151 +/- 23 pmol/l, respectively, and abolished partly the inhibition of Na+-K+-ATPase activity (64.9 +/- 7.6% of controls). These changes corresponded to the degree of ECFV alteration. Our results suggest that both natriuretic principles are activated during ECFV expansion in CRF, probably as a corrective mechanism, with a tendency to normalize when ECFV is reduced during hemodialysis.
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PMID:Atrial natriuretic peptide concentration and natriuretic hormone activity in plasma of patients with chronic renal failure. 285 Sep 86

The epidemiology and etiology, pathophysiology, diagnosis, and treatment of congestive heart failure (CHF) are reviewed. CHF affects as many as 4 million Americans and is one of the most prevalent causes of death in hospitalized patients. Major risk factors for developing CHF include advanced age, male sex, hypertension, coronary artery disease, smoking, hypercholesterolemia, diabetes mellitus, and rheumatic heart disease. Heart failure results from decreased intrinsic myocardial contractility caused by one or more of three changes: (1) altered adrenergic nervous system function, (2) impaired delivery of calcium to contractile elements in the heart, and (3) reduced myosin-ATPase activity in the myocardium. The disease is progressive, and no intervention has yet been found to stop it effectively. CHF is diagnosed based on subjective signs and symptoms and objective assessment using auscultation, ECG, chest roentgenogram, laboratory tests, and noninvasive and invasive tests. Treatment of CHF begins with restriction of physical activity and sodium intake. Pharmacologic interventions start with either digitalis glycosides or thiazide diuretics; both may be used concomitantly as the disease progresses. Current studies are focusing on the use of angiotensin-converting enzyme inhibitors as first-line agents for CHF. When CHF worsens, loop diuretics are substituted for or added to the thiazide diuretics, and vasodilators are added to reduce the workload on the heart. Other inotropic agents, including the new bipyridine derivatives, may also be used. In patients not responding to these and other aggressive therapeutic interventions, cardiac transplantation is the only option. Despite advances in management of CHF, little improvement in overall survival has been demonstrated, and no intervention has stopped or reversed the progression of CHF.
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PMID:Current concepts in clinical therapeutics: congestive heart failure. 287 92

The oxidative phosphorylation as well as calcium transporting properties of heart mitochondria and calcium transport activities of the fragments of the sarcoplasmic reticulum (microsomes) were studied during the life span of cardiomyopathic hamsters (UM-X7.1). Control healthy hamsters of the same age group were used for comparison. No changes in the oxidative phosphorylation ability of cardiomyopathic mitochondria were seen at early and moderate stages of heart failure; however, at severe stages, mitochondrial respiratory functions, but not the ADP:0 ratio, were impaired. Both creatine phosphate and ATP contents were decreased without any significant changes in the ATPase activities of myofibrils from the failing hearts. Heart mitochondria from cardiomyopathic animals at severe stages of failure exhibited less calcium binding and uptake activities in comparison with the control values whereas no changes in the mitochondrial calcium binding and uptake were seen in cardiomyopathic hamsters which showed no clinical signs of heart failure. Although mitochondrial calcium binding in cardiomyopathic hearts at early and moderate stages of failure was decreased, mitochondrial calcium uptake was not significantly different from the control. Microsomal calcium binding activity, unlike calcium uptake activity, was decreased in the hearts of cardiomyopathic hamsters without any signs of heart failure. Both calcium binding and calcium uptake activities of microsomes from animals with early, moderate and severe heart failure were less in comparison with the control values but were not associated with any changes in the Ca2+-stimulated ATPase activity. These results suggest that changes in the process of mitochondrial energy production and mitochondrial Ca2+-transport may be secondary to other factors whereas alterations in the sarcoplasmic reticular Ca2+-transport may lead to the development of heart failure in the cardiomyopathic hamsters.
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PMID:Impairment of mitochondrial and sarcoplasmic reticular functions during the development of heart failure in cardiomyopathic (UM-X7.1) hamsters. 294 28

The activity of the azide-insensitive Ca2+-dependent ATPase (highly enriched in myofibrillar ATPase activity) was studied in specimens of both right and left atria which were taken from patients with ischemic and/or valvular heart disease during coronary by pass and/or valvular substitution. A significantly lower enzymatic activity was found in atrial specimens from patients with left ventricular heart failure in comparison to the atrial fragments obtained from the patients with normal heart function. Such an inhibition reflected a significant increase in the Km of the enzyme for ATP and was associated with a concomitant reduction in Vmax, both more evident in the left atrial fragments. Moreover, tissue homogenates of atrial specimens from failing hearts exhibited a lower protein SH group content when compared to the atrial homogenates from the heart with normal left ventricular heart function.
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PMID:Analysis of azide-insensitive Ca2+-dependent ATPase activity in atrial specimens from patients with coronary or valvular heart disease. 295 56

Force development and shortening by cardiac muscle occur as a result of the interaction between actin and myosin within the myofibrillar lattice. This interaction is dependent upon intracellular ionized calcium and is controlled by the troponin-tropomyosin regulatory proteins situated along the actin filament. In this study, we compared the myofibrillar content and myofibrillar Mg-ATPase activity of normal human ventricular muscle with that of ventricular muscle from patients in end-stage failure caused by coronary artery disease or cardiomyopathy and ventricular muscle from patients with heart failure due to mitral valve insufficiency. The results show that the amount of myofibrillar protein (mg/g wet wt ventricle) in hearts in end-stage failure (coronary artery disease and cardiomyopathy) is significantly lower compared with normal hearts and hearts in failure due to mitral valve insufficiency. However, the Mg-ATPase activity of myofibrils from hearts in both end-stage failure and failure due to mitral valve insufficiency is significantly lower compared with myofibrils from normal hearts. The data suggest that the reduction in the amount of myofibrillar protein in ventricular tissue is a pivotal event that may be responsible for the progression of heart disease to the point of end-stage failure.
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PMID:Changes in myofibrillar content and Mg-ATPase activity in ventricular tissues from patients with heart failure caused by coronary artery disease, cardiomyopathy, or mitral valve insufficiency. 296 7

In most animal species, left ventricular hypertrophy due to pressure overload is associated with an advantageous increase of the "slow" V3 isomyosin. In contrast, in spontaneously hypertensive turkeys, the development of left ventricular hypertrophy is associated with the synthesis of a "fast" V1-like isomyosin, with high incidence of cardiac failure. This could be related to the high catecholamine levels found in these animals. This is why we studied the ventricular myosin pattern after lowering of blood pressure and regression of cardiac hypertrophy obtained by means of labetalol, and alpha- and beta-blocking drug which inhibits the effects of catecholamines. From the 2nd to the 32nd week of age, 22 turkeys were treated with increasing doses of p.o. labetalol (from 20 to 35 mg/kg body weight daily) and 16 other turkeys were given daily p.o. placebo. Blood pressure and heart rate were periodically measured by an indirect method. After sacrifice, the degree of cardiac hypertrophy was evaluated by the biventricular weight to body weight ratio, ventricular myosin was purified, Ca++-activated ATPase activity assessed, and ventricular myosin pattern was determined by two-dimensional gel electrophoresis of myosin heavy chains. Plasma and cardiac catecholamines were measured by high performance liquid chromatography. Throughout the study period, blood pressure and heart rate were significantly reduced in the labetalol-treated animals as compared to the untreated ones. At the end of the study period, the ventricular mass was significantly lower in the labetalol group. Nevertheless, no differences were observed in ventricular myosin pattern and Ca++-activated ATPase activity levels between the two groups. In the labetalol group, an increase in plasma catecholamines and only a slight, but not significant, increase in cardiac catecholamines was found. These data indicate that in spontaneously hypertensive turkeys, the synthesis of the "fast" V1-like isomyosin is not influenced by known pathophysiological stimuli like blood pressure, cardiac hypertrophy and catecholamines.
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PMID:Ventricular myosin pattern of spontaneously hypertensive turkeys is unaffected by labetalol treatment. 297 Aug 41

The present study has examined early cellular effects of chronic adriamycin administration to dogs using a protocol (1 mg/kg/week to a total cumulative dose of 240 mg/m2) producing significant but small reductions in ejection fraction and stroke volume as determined echocardiographically prior to the development of clinical or radiological manifestations of heart failure. At this early phase of cardiomyopathy, significant reduction (P less than 0.05) in sarcoplasmic reticulum Ca2+, K+-ATPase was observed without any change in mitochondrial, lysosomal or sarcolemmal marker enzymes. Myocardial calcium (P less than 0.01) and glutathione (P less than 0.001) levels were increased significantly. Detailed analysis of myocardial phospholipid profiles failed to show any significant differences between control and treated dogs. In contrast, red cell membranes showed increased phosphatidylcholine (PC) and decreased phosphatidylserine (PS) contents, resulting in a significant increase in PC/PS ratio (P less than 0.05). No significant changes were detected in activities of catalase, superoxide dismutase or glutathione peroxidase in erythrocytes or myocardial tissue from control and adriamycin-treated animals. A significant (P less than 0.05) elevation in plasma sialic acid was observed following adriamycin treatment. Our results suggest that early adriamycin-induced damage is unlikely to result from alterations in cellular processes protecting tissues against oxidant injury. Regression analysis indicated that, of the various abnormalities observed, only the elevated myocardial calcium levels and the increases in plasma sialic acid correlated with the degree of myocardial functional impairment. Our findings suggest the presence of sarcolemmal alterations in Ca2+ handling in early adriamycin-induced myocardial injury and indicate that measurement of plasma sialic acid should be further investigated as a possible noninvasive indicator of impending adriamycin cardiotoxicity.
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PMID:Adriamycin cardiomyopathy: implications of cellular changes in a canine model with mild impairment of left ventricular function. 299 97


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