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

End stage heart failure due to ischemic (ICM) or dilated (DCM) cardiomyopathy is characterized by a dilated, relatively thin-walled ventricle. The hypothesis has been proposed that the structural basis of ventricular expansion is due to side-to-side slippage of myocytes within the wall. Although this represents one potential mechanism for the observed phenomena of chamber dilatation and subsequent wall thinning, the degree of slippage claimed is not necessarily in harmony with the magnitude of chamber enlargement and mural thinning. Moreover, sarcomere extension was not examined in the base to the apical regions of the heart, leaving open the question as to the role of changes in resting sarcomere length in acute chamber dilatation. In this regard, an alternative etiology for the detrimental cardiac architectural rearrangement seen in dilated failure can be supplied by postulating the occurrence of maladaptive remodeling of cardiac myocyte morphology. In this model, myocytes increase in length by an increase in the number of sarcomeres in series, thus increasing chamber diameter in an attempt to maintain cardiac output. However, these cells do not enlarge to any significant degree in the transverse diameter preventing the heart from developing adequate force. This hypothesis is supported by recent evidence from patients with ICM and DCM indicating that myocyte lengthening alone could account for all the dilatation observed. Furthermore, it appears that the thinning of the ventricular wall in failure is due to inadequate transverse growth of cardiac myocytes coupled with scattered myocyte cell loss throughout the ventricular wall.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Structural remodeling and mechanical dysfunction of cardiac myocytes in heart failure. 760 3

Eleven DCM patients who were found to have significant background hypertension from an echocardiographic assessment of the role of hypertension in DCM form the subject of this follow-up study. This was to test the reliability or otherwise of this investigative method which is supposed to identify DCM patients who would be expected to manifest hypertension with traditional anti-heart failure treatment. Results suggest a sensitivity of about 73% and specificity of 36%. It has a false positive potential in young females with the "Zaria-type" peripartum cardiomyopathy where fluid overload and not intrinsic myocardial failure is responsible.
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PMID:Behaviour of blood pressure in dilated cardiomyopathy patients suspected significantly hypertensive at echocardiography. 767 59

Rabbit Coronavirus (RbCV) infection was divided into two phases based upon day of death and pathologic findings. During the acute phase (days 2-5) heart weights (HW) and heart weight-to-body weight (HW/BW) ratios were increased with striking dilation of the right ventricle. These changes as well as increased dilation of the left ventricle were especially pronounced during the subacute phase (days 6-12). Myocytolysis, pulmonary edema, and degeneration and necrosis of myocytes, were seen during both phases. Myocarditis, pleural effusion, calcification of myocytes, and congestion in the liver and lungs were seen in the subacute phase. Electrocardiograms (ECGs) exhibited low voltage, nonspecific ST-T wave changes, sinus tachycardia, occasional ventricular and supraventricular premature complexes and 2(0) AV block consistent with myocarditis and heart failure. Forty-one percent of the survivors exhibited increased HW and HW/BW ratios, biventricular dilation, interstitial and replacement fibrosis, myocyte hypertrophy and myocarditis. ECGs exhibited nonspecific ST-T wave changes, sinus arrhythmia, occasional ventricular and supraventricular premature complexes and 2(0) AV block. These data suggest that RbCV infection may result in viral myocarditis and heart failure with a proportion of survivors progressing into DCM.
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PMID:Electrocardiographic changes following rabbit coronavirus-induced myocarditis and dilated cardiomyopathy. 820 55

Turkey poults fed furazolidone (Fz) in high concentrations (700 ppm) develop dilated cardiomyopathy (Fz-DCM). We tested whether five cardioactive agents were cardioprotective in this model of heart failure, ie, whether they prevented dilatation and wall thinning and improved contractile performance. We compared the effects of chronic administration of a beta 1-selective and a nonselective beta-receptor antagonist, an alpha-receptor antagonist, and two Ca2+ channel antagonists in the presence of Fz administration. The greatest cardioprotection was found with treatment with either propranolol or nifedipine. At the gross morphological level, the effect of propranolol (a nonselective beta-adrenergic antagonist) was greater than the effect of atenolol (a selective beta 1-adrenergic antagonist), and the effect of nifedipine was greater than that of verapamil (Ca2+ channel antagonists), with all agents more cardioprotective than phenoxybenzamine (an alpha 1-adrenergic > alpha 2-adrenergic antagonist). Differences in cardioprotective efficacy of each agent increased with increased concentration. These data indicate that the dose and choice of a specific type of Ca2+ channel antagonist or beta-receptor antagonist might be important in the treatment of dilated cardiomyopathy. All agents that were cardioprotective caused similar functional improvements at both the whole heart and isolated muscle levels. Compared with control animals, Fz-DCM animals showed a significant reduction in peak left ventricular (LV) developed pressure (92 +/- 17 versus 143 +/- 24 mm Hg, P < .05), +dP/dt (1151 +/- 219 versus 2454 +/- 549 mm Hg/s), and -dP/dt (1128 +/- 291 versus 1875 +/- 396 mm Hg/s), with a significant increase in LV end-diastolic volumes (2.8 +/- 0.7 versus 0.16 +/- 0.1 mL for control animals, P < .05). In contradistinction, LV + dP/dt and -dP/dt values for animals receiving Fz plus a cardioactive agent that demonstrated cardioprotection were not significantly different from control values. Peak LV developed pressures were also similar for Fz animals receiving an agent that demonstrated cardioprotection and control animals not receiving any pharmacologic agent. Isolated muscles from Fz-DCM animals as well as animals receiving Fz plus cardioprotective pharmacologic agents responded normally with regard to increasing extracellular Ca2+ concentrations. Peak twitch forces were greater for animals receiving cardioprotective agents plus Fz than control animals not receiving any pharmacologic agents or Fz alone. At higher stimulation rates, Fz-DCM muscles demonstrated a significantly reduced peak twitch force (4 +/- 0.5 versus 1.5 +/- 0.4 g/mm2 for control muscles versus Fz-DCM muscles, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Differences in cardioprotective efficacy of adrenergic receptor antagonists and Ca2+ channel antagonists in an animal model of dilated cardiomyopathy. Effects on gross morphology, global cardiac function, and twitch force. 822 79

The ryanodine-sensitive Ca2+ release channel (RyaCRC) of the sarcoplasmic reticulum plays a key role in the intracellular Ca2+ handling in cardiomyocytes. Altered expression of the RyaCRC has been supposed to contribute to abnormal cellular Ca2+ handling and to myocardial dysfunction in dilated and ischemic cardiomyopathy. In the present study the 3H-ryanodine binding site in human myocardial homogenates was characterized and the density of the RyaCRC (which corresponds to the cardiac ryanodine receptor) was determined in nonfailing and in failing human myocardium. Homogenates were prepared from nonfailing left ventricular myocardium from the hearts of 5 organ donors (NF) and from failing myocardium from 14 explanted hearts of transplant recipients with end-stage heart failure resulting from dilated (DCM, n = 5) or ischemic (ICM, n = 9) cardiomyopathy. Radioligand saturation binding experiments revealed a specific, high-affinity 3H-ryanodine binding site (Kd-values: NF: 0.65 +/- 0.11 nmol/l, DCM: 0.66 +/- 0.09 nmol/l, ICM: 0.88 +/- 0.18 nmol/l; n.s.) in all preparations. Specific 3H-ryanodine binding depended on the free Ca2+ concentration in the assay. It was maximal at 3-100 micro mol/l Ca2+. The binding was inhibited by the RyaCRC antagonists ruthenium red (Ki-value: 0.32 [0.18-0.56] micromol/l, n = 5) and Mg2+ (Ki-value: 2.95 [1.23-7.11] mmol/l, n = 5). The RyaCRC density was 103.5 +/- 11.9 fmol/mg protein in nonfailing myocardium. There was no significant change in the RyaCRC density in dilated or ischemic cardiomyopathy (112.4 +/- 17.1 and 122.7 +/- 13.9 fmol/mg protein) compared to nonfailing control myocardium. In summary, 3H-ryanodine binds specifically and with high-affinity to the RyaCRC in human myocardium. There is no change in the RyaCRC density in failing myocardium of patients with DCM or ICM in comparison to non-failing controls.
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PMID:The ryanodine binding sarcoplasmic reticulum calcium release channel in nonfailing and in failing human myocardium. 875 Sep 20

A 60-year-old man with severe DCM was scheduled for a herniorrhaphy under epidural anesthesia using fentanyl. Three months prior to operation, the patient suffered heart failure associated with life-threatening ventricular arrhythmia. The former was successfully treated with pimobendan as the main constituent of medication, but the latter was not responsive to various antiarrhythmic drugs with the exception of aprindine. On the day of operation and for two days postoperatively, pimobendan was administered daily. A sudden drop in systemic blood pressure and central venous pressure (CVP) during anesthesia, as well as the tendency to hypotensive status in the postoperative period were well regulated with continuous infusion of dopamine and dobutamine via CVP catheter probably due to the effect of up-regulation of pimobendan, together with adjustment of the volume of intravenous fluids. No dangerous ventricular arrhythmia were observed. Thereafter the patient made uneventful progress and was discharged on the 8th postoperative day.
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PMID:[Epidural anesthesia for herniorrhaphy in a patient with severe dilated cardiomyopathy (DCM) under pimobendan control]. 902 94

Annexins are a unique family of membrane-associated, Ca2+ and phospholipid-binding proteins found in various tissues. Among the 12 isoforms, Annexin II, V and VI exist in heart tissue in the highest amounts. Annexin VI has been shown to affect intracellular Ca2+ cycling and contractility in isolated cardiomyocytes. Annexin V is present in both cardiomyocytes and non-myocyte cell types in the heart and may play a role in the regulation of cellular ion fluxes, organization and secretion, while the cardiac effects of annexin II are unclear. To identify changes in annexin II, V and VI isoforms that might occur in human heart failure, we measured mRNA and protein levels of these three annexins in transplanted left ventricular tissue of 12 patients with end-stage congestive heart failure due to coronary artery disease (CAD, n=6) or idiopathic dilated cardiomyopathy (DCM, n=6) who underwent cardiac transplantation. Normal heart tissue (C, n=6) was used as a control. Northern blot analyses showed a significant decrease (61%) in annexin VI mRNA levels in heart failure patients compared with controls (1.08+/-0.16 v 2.79+/-0.20 A.U.C. unit, determined by laser densitometry, mean+/-s.e.). In contrast, we found a 67% increase (2. 32+/-0.27 v 3.88+/-0.29) in annexin II mRNA levels and a two-fold increase (1.00+/-0.24 v 2.21+/-0.29) in annexin V mRNA levels in cardiomyopathic hearts as compared to normal hearts. Western blot analyses demonstrated a corresponding decrease (46.1%) in annexin VI protein levels in the heart failure group as compared to controls (2. 63+/-0.22 v 4.88+/-0.52), while annexin II protein levels showed a significant 40.7% increase in patients with heart failure compared to those in normal hearts (5.08+/-0.67 v 3.61+/-0.32). Annexin V protein levels were also significantly increased (45%) in heart failure patients compared with normal (2.14+/-0.19 v 1.48+/-0.11). No difference in either annexins II, V or VI mRNA and protein levels were found between CAD and DCM patients. We conclude that human end-stage heart failure is associated with a down regulation of annexin VI and up regulation of annexin II and V proteins. Coordinate changes were observed in steady-state mRNA levels. These results suggest that these annexin isoforms may contribute to the regulation of intracellular Ca2+ homeostasis in the cardiomyopathic heart.
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PMID:Altered cardiac annexin mRNA and protein levels in the left ventricle of patients with end-stage heart failure. 951 22

Cell death can be induced by 2 different mechanisms: necrosis and apoptosis. Necrosis, on the one hand, is usually caused by unphysiological stress factors such as hyperthermia or hypoxia, apoptosis, on the other hand, is part of the normal organ development and controls for example immune responses. Morphologically, necrosis is characterized by swelling of cells and their organelles leading to the disruption of the cell membrane, which in turn causes an inflammatory reaction in the surrounding tissue. Morphological and biochemical criteria (Figure 1, Table 1) of apoptosis are the condensation of chromatin leading to the development of apoptotic bodies or membrane-enclosed vesicles containing oligonucleosomal DNA fragments. Important diagnostic tools of cell death (Table 2), such as the TUNEL test (Figure 2) or gel electrophoresis of extracted DNA (Figure 3) are based on the above mentioned biochemical characteristics, but a reliable differentiation of apoptotic versus necrotic processes is not always possible. Experimental studies in animals and studies in various diseases of the cardiovascular system were able to show that apoptosis in myocytes can be induced, an issue that has long been discussed controversially. Ischemia, reperfusion, and myocardial infarction were also shown to lead to apoptosis in cardiomyocytes, whereas cell destruction was caused mainly by necrosis. Several authors (Table 3) demonstrated apoptotic indices in cardiomyocytes of patients with dilatated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and patients with acute infarction from 0.25 to 35% by the use of the TUNEL test. Others were able to demonstrate an elevated expression of Fas-receptor in cells of atheroslerotic plaques in patients with atherosclerosis and high indices of apoptotic cardiomyocytes in patients with chronic heart failure. We investigated endomyocardial biopsies of patients with inflammatory cardiomyopathy, DCM without inflammatory reaction but the presence of adenoviral or cytomegaloviral genome and idiopathic DCM using the TUNEL test. The percentage of apoptotic cardiomyocytes in biopsies of patients with DCMi was 1.03 and in biopsies of patients with adenoviral genome 0.25, whereas in all other groups no apoptosis was found. If apoptosis plays a major role in myocardial diseases such as heart failure, arrhythmia and others, blocking this mechanism will have to be considered as a therapeutical strategy. Therefore, studies on the extent of apoptotic processes in diseased versus healthy cardiac tissue are of great importance.
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PMID:[Cell death in inflammatory heart muscle diseases--apoptosis or necrosis?]. 1041 44

Only scarce information is available on the activity and modifications of the cardiac endothelin (ET)-1 system in heart failure due to ischemic (ICM) or idiopathic dilated (DCM) cardiomyopathy. The activity of the ET-1 system was investigated by measuring cardiac ET-1 and big ET-1 formation and quantifying cardiac mRNA for prepro-ET-1 (ppET-1), ET-converting enzyme-1, and ET(A) and ET(B) receptors both in myocardium and in isolated myocytes using Northern blot, reverse transcription-polymerase chain reaction, and in situ hybridization in 22 patients with DCM and 20 with ICM who underwent cardiac transplantation and in 7 potential heart transplant donors (nonfailing hearts). Notwithstanding a similar increase of plasma ET-1 in the 2 groups, cardiac ET formation, mRNA levels for ppET-1, and ET(A) and ET(B) receptors were higher on both the myocardium and isolated myocytes from ICM than on those from DCM hearts (P<0.001 for all). ppET-1 and ET-converting enzyme-1 mRNAs were expressed on myocytes and endothelial and interstitial cells in ICM, whereas in DCM and nonfailing hearts they were mainly expressed on nonmyocyte cells. In both ICM and DCM, the ET(A) mRNA signal was expressed on both myocytes and nonmyocyte cells, whereas ET(B) mRNA was almost exclusively localized on nonmyocyte cells. ET(A)- and ET(B)-specific receptor binding was increased on both myocytes and cardiac membranes, showing a positive correlation with left ventricular ejection fraction in ICM (r=0.78 and 0.70) but not in DCM patients. The present results show that human ventricular myocytes express all of the components of the ET-1 system, which is selectively upregulated in ICM patients and appears to be functionally important in the maintenance of cardiac function.
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PMID:Selective upregulation of cardiac endothelin system in patients with ischemic but not idiopathic dilated cardiomyopathy: endothelin-1 system in the human failing heart. 1070 Apr 41

In heart failure a decreased function of SERCA 2 has been demonstrated. The present study aimed at investigating the relation between sarcoplasmic reticulum-Ca2+-load (SR-Ca2+-load) and the activity of the SERCA 2. SR-Ca2+ load was evaluated by measuring posttetanic potentiation (PTP) in human nonfailing (NF, n = 10) and endstage failing myocardium (DCM, n = 11). In addition, the effect of cyclopiazonic acid (CPA), a specific inhibitor of SERCA 2, on PTP was studied in both NF and DCM. In crude membrane preparations from the same hearts the maximal SERCA 2 activity was determined and correlated with the PTP. In failing myocardium the PTP was significantly reduced compared to nonfailing myocardium (13.7+/-0.75 mN/mm2 vs. 17.1+/-1.55 mN/mm2, p<0.05, +/- SEM). When PTP was studied in the presence of increased extracellular Ca2+-concentrations, the difference between NF and DCM was further pronounced. CPA decreased PTP in both nonfailing and failing human tissue. The maximal SERCA 2 activity was significantly reduced in failing myocardium (NF 267+/-18.5 nmol ATP/mg protein x min(-1) vs. DCM 191+/-13.4 nmol ATP/mg protein x min(-1), p<0.05, +/- SEM). Correlation of the PTP and maximal SERCA 2 activity revealed a close correlation between both parameters in NF and DCM. In summary, the presented results suggest that reduced SERCA 2 activity in DCM influences posttetanic force potentiation probably through a reduced SR-Ca2+-load.
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PMID:Diminished posttetanic potentiation in failing human myocardium. 1109 61


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