Oxygen transport to muscle during exercise in chronic congestive heart failure secondary to idiopathic dilated cardiomyopathy

In chronic heart failure, oxygen delivery during exercise is impaired mainly because of failure of cardiac output to increase normally. Compensatory mechanisms are hemoglobin concentration increase, right-ward shift in the oxyhemoglobin dissociation curve, and blood flow redistribution from the nonexercising organs to the exercising muscles.     

Effects of maximally tolerated oral therapy on the six-minute walking test in patients with chronic congestive heart failure secondary to either ischemic or idiopathic dilated cardiomyopathy

In patients with heart failure, therapy with "maximally tolerated" oral doses of diuretics, vasodilators, and digitalis results in a significant increase in the distance walked during the 6-minute walking test, compared with conventional therapy at "standard" doses, indicating an improvement in exercise tolerance. The 6-minute walk test is a simple, inexpensive, and well-tolerated test to measure changes in exercise tolerance induced by pharmacologic interventions, even on a short-term basis.     

Hemodynamic profile of submaximal constant workload exercise in patients with heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

Medical thinkers in China visualized the liver in microcosmal and macrocosmal terms. An anatomical tradition did not exist, hence the liver was described grossly in broad outline. It was recognized as being functionally important in the movement of qi (vital energy) and storage of xue ('blood'). The liver corresponded to various phenomena in both the natural and social orders, according to the scheme of yin yang and five phases. These interrelationships provided the basis for the diagnosis and treatment of liver dysfunctions. The disorders fell into three general groups: (i) hepatic qi stasis; (ii) hepatic yang excess with yin deficiency; and (iii) hepatic yin insufficiency. The signs and symptoms represented the logical outcomes of the disturbed physiology. Acupuncture, moxibustion and herbal drugs were used to redress the imbalance of hepatic qi and yin-yang. The impact of Western medicine led traditional authors to recognize the hepatobiliary role in bile secretion and in jaundice. The exchange between the Western and Chinese medical traditions revealed that active agents were included in the Chinese formulary, such as glycyrrhizin, which has recently been shown to be beneficial in chronic viral hepatitis.     

Temporary mechanical left heart support. Recovery of heart function in patients with end-stage idiopathic dilated cardiomyopathy

BACKGROUND: Implantation of a mechanical cardiac support system (MCSS) in patients with idiopathic dilated cardiomyopathy (IDC) may improve cardiac function and allow explantation of the device. Our experience now includes 13 patients who have been "weaned" from MCSS and we report about the overall results of this treatment as well as the effects of ventricular unloading on cardiac function, anti-beta 1-adrenoceptor-autoantibody (A-beta 1-AAB) level and the degree of myocardial fibrosis. METHODS: 13 patients with non-ischemic IDC who had been admitted here in cardiogenic shock (CI < 1.61.min-1.m2, left ventricular ejection fraction [LVEF] < 16% and left ventricular internal diameter in diastole [LVIDd] > 68 mm) and who all tested positive for A-beta 1-AABs were implanted with an uni-(12 patients) or a biventricular (1 patient) mechanical assist device. Echocardiographic evaluation and A-beta 1-AAB-level-monitoring was routinely performed after implantation and explantation of the MCSS and the degree of myocardial fibrosis was assessed at the time of implantation and after explantation. RESULTS: During a mean duration of mechanical support of 236 +/- 201 days (range: 30 to 794 days), LV-EF improved to a mean of 46% and LVIDd decreased to a mean value of 56 mm in these 13 patients. A-beta 1-AABs decreased and disappeared 11.7 weeks after implantation of the device and did not reincrease thereafter. The highly pathologic degree of fibrosis at the time of implantation diminished to normal values about 1 year after explantation. One patient died of anesthesiologic complications and another patient shortly presented with a new episode of cardiac insufficiency 6 months after explantation. He was implanted again with an univentricular assist device was successfully transplanted 3 weeks later. Mean observation period of the remaining 11 patients now amounts to 12.6 +/- 9.77 (range: 3 to 26) months after explantation of the device--as of May, 31, 1997--with a cumulative observation period of 139 patient months. CONCLUSION: Temporary implantation of a MCSS may normalize cardiac function in selected patients with IDC. The striking degree of myocardial fibrosis can reduce to normal values after explantation of the device. A-beta 1-AABs disappear during ventricular unloading and do not increase thereafter. "Weaning" from mechanical device may constitute an alternative treatment to cardiac transplantation in selected patients.     

Problems of idiopathic congestive cardiomyopathy

It is reported on the course of an idiopathic congestive cardiomyopathy in a younger man which could be observed during three years. After a longer period free of symptoms acutely appeared the signs of a myocardial failure, in which case disturbances of cardiac rhythm at length caused death. In detail the clinical fingings, pathologo-anatomical changes as well as the differential-diagnostic considerations are discussed, which are important for the demarcation of the other forms of the idiopathic and secondary cardiomyopathies.     

Dystrophin analysis in idiopathic dilated cardiomyopathy

Idiopathic dilated cardiomyopathy (DCM) is characterised by ventricular dilatation and impaired systolic function resulting in congestive heart failure and frequently death. A dilated cardiomyopathy is common in patients with symptomatic Duchenne/Becker muscular dystrophy, a disease caused by dystrophin gene defects. However, cardiomyopathy is rarely the predominant clinical feature of this form of muscular dystrophy. To determine whether dystrophin gene defects might account for a significant number of patients with apparently isolated idiopathic DCM, we performed dystrophin gene analysis in 27 DCM patients, who were ascertained as part of a prospective study on idiopathic DCM. No dystrophin gene defects were found in our patients, whose average age was 50 years. These data suggest that dystrophin defects are not a common cause of idiopathic DCM in this age group in the absence of skeletal muscle cramps or weakness.     

Do specific HLA antigens predispose to ischaemic heart disease or idiopathic dilated cardiomyopathy?

BACKGROUND: The aetiology of idiopathic dilated cardiomyopathy is believed to have an immunological component. Association with human leucocyte antigens (HLAs) has been previously reported, particularly with HLA-DR4. AIM: To determine the association of HLA type with diagnosis in a group of patients assessed for heart transplantation. METHODS: A comparison was made of frequencies of HLA types in patients with a diagnosis of idiopathic dilated cardiomyopathy or (n = 98) ischaemic heart disease (n = 170) and in controls from the North Western region (n = 857). RESULTS: Neither the patients with idiopathic dilated cardiomyopathy nor those with ischaemic heart disease showed a significant increase or decrease in any HLA frequency compared with the controls. CONCLUSION: These results suggest that there is no HLA association with idiopathic dilated cardiomyopathy or ischaemic heart disease. This conflicts with the results of some previous studies.     

Role of secondary prevention in congestive heart failure due to coronary artery disease

BACKGROUND: It is unknown whether genetic factors predispose patients to idiopathic pancreatitis. In patients with cystic fibrosis, mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene typically cause pulmonary and pancreatic insufficiency while rarely causing pancreatitis. We examined whether idiopathic pancreatitis is associated with CFTR mutations in persons who do not have lung disease of cystic fibrosis. METHODS: We studied 27 patients (mean age at diagnosis, 36 years), 22 of whom were female, who had been referred for an evaluation of idiopathic pancreatitis. DNA was tested for 17 CFTR mutations and for the 5T allele in intron 8 of the CFTR gene. The 5T allele reduces the level of functional CFTR and is associated with an inherited form of infertility in males. Patients with two abnormal CFTR alleles were further evaluated for unrecognized cystic fibrosis-related lung disease, and both base-line and CFTR-mediated ion transport were measured in the nasal mucosa. RESULTS: Ten patients with idiopathic chronic pancreatitis (37 percent) had at least one abnormal CFTR allele. Eight CFTR mutations were detected (prevalence ratio, 11:1; 95 percent confidence interval, 5 to 23; P<0.001). In three patients both alleles were affected (prevalence ratio, 80:1; 95 percent confidence interval, 17 to 379; P<0.001). These three patients did not have lung disease typical of cystic fibrosis on the basis of sweat testing, spirometry, or base-line nasal potential-difference measurements. Nonetheless, each had abnormal nasal cyclic AMP-mediated chloride transport. CONCLUSION: In a group of patients referred for evaluation of idiopathic pancreatitis, there was a strong association between mutations in the CFTR gene and pancreatitis. The abnormal CFTR genotypes in these patients with pancreatitis resemble those associated with male infertility.     

Actin mutations in dilated cardiomyopathy, a heritable form of heart failure

To test the hypothesis that actin dysfunction leads to heart failure, patients with hereditary idiopathic dilated cardiomyopathy (IDC) were examined for mutations in the cardiac actin gene (ACTC). Missense mutations in ACTC that cosegregate with IDC were identified in two unrelated families. Both mutations affect universally conserved amino acids in domains of actin that attach to Z bands and intercalated discs. Coupled with previous data showing that dystrophin mutations also cause dilated cardiomyopathy, these results raise the possibility that defective transmission of force in cardiac myocytes is a mechanism underlying heart failure.     

An analytical comparison of cobalt cardiomyopathy and idiopathic dilated cardiomyopathy

Toxic cardiomyopathy (TC) has a rapid clinical course and morphologically resembles idiopathic dilated cardiomyopathy (IDC). To further characterize TC, we used light microscopy to compare lesions caused by cobalt (Co) to those of IDC. Cobalt levels were also measured as a chemical marker to differentiate TC from IDC. We reviewed cases with TC and IDC and excluded all cases with chemotherapy-induced myopathy and catecholamine toxicity as well as cases with possible infectious, ischemic, or hypersensitivity-induced myopathies. We compared the light microscopic findings of 12 TC cases of 12 cases of IDC, and measured trace Co levels on digested heart tissue samples. The TC cases had prominent myofibrillar loss and atrophy; no cases had neutrophil infiltration or frank myocyte necrosis. In contrast, IDC had minimal myofibril loss and atrophy. Cobalt levels in the range of 0.6 to 5.45 micrograms/g of dry tissue were obtained for the TC cases, while IDC demonstrated Co levels of 0.01-0.2 micrograms/g. Distinction between TC and IDC is predominantly a function of myocyte change, with TC showing myofibrillar loss and atrophy in the absence of inflammatory infiltrates and fibrosis; IDC is predominantly associated with myocyte hypertrophy, atrophy, and fibrosis.     

Enalapril reduces QTc dispersion in mild congestive heart failure secondary to coronary artery disease

Intranasal administration of protein antigen is an efficient way to induce mucosal tolerance. Suppressive mechanisms that might be involved in this phenomenon include down-regulation of T-helper type-1 (Th1)-mediated processes by Th2 cells. However, since Th2 responses can also be subjected to mucosal tolerance, we wanted to investigate whether suppression of a typical Th1 response, such as a delayed-type hypersensitivity (DTH) reaction by intranasal tolerance induction, was causally related to up-regulation of Th2 responses. We therefore treated mice either systemically or locally with anti-interleukin-4 (IL-4) or anti-IL-10 antibodies before intranasal tolerance induction or before sensitization for DTH to see whether we could prevent or abrogate tolerance. Although the up-regulation of antigen-specific IgE levels in tolerant mice could be prevented by anti-IL-4 treatment, the extent of tolerance as measured by suppression of DTH was not affected. We therefore conclude that up-regulation of Th2 responses observed after intranasal tolerance induction is an additional or consequential rather than a necessary reaction.     

Amiodarone in congestive heart failure

Originally developed as an antianginal agent, amiodarone was soon found to have antiarrhythmic properties and to be a non-competitive inhibitor of alpha and beta-adrenergic receptors. Many trials studying the use of amiodarone in patients with heart failure have now been performed and are reviewed in this article. The trials appear to show that amiodarone possesses significant antiarrhythmic activity, even in heart failure patients. The drug appears to be well tolerated and proarrhythmia is uncommon. Based on the findings of a large Argentinian randomised trial (GESICA) and the Congestive Heart Failure Survival Trial of Antiarrhythmic Therapy (CHF STAT), it would appear there is a role for amiodarone in patients with non-ischaemic cardiomyopathy, but prospective studies are required to confirm this. The benefit of amiodarone in patients with non-ischaemic cardiomyopathy might be related to the beta-blocking effect that is seen with the use of conventional beta-blockers. Further studies, including the Sudden Cardiac Death Heart Trial (SCD HeFT), should help determine the role of amiodarone in heart failure patients.     

Evaluation of the regional responsivity to ryanodine of human myocardium from patients with idiopathic dilated cardiomyopathy and secondary cardiomyopathies

Nesidioblastosis associated with progressive weight loss and hyperglycemia was diagnosed in two mid-adult, wild-caught, male squirrel monkeys (Saimiri sciureus). Hyperglycemia, glucosuria, and abnormal glucose tolerance test results were found when the monkeys were presented for clinical evaluation for chronic weight loss, episodic dehydration, hypothermia, and lethargy. Immunohistochemical studies of the pancreatic tissue demonstrated that the proliferating endocrine cells stained predominantly glucagon-positive in the most severely affected monkey.     

Hemorrhagic ascites due to congestive heart failure

Ascites due to congestive heart failure (CHF) is characteristically serous in gross appearance. Although hemorrhage into ascites commonly indicates a malignant or inflammatory cause, cirrhosis of the liver is a well known cause of bloody ascites. We report a case of hemorrhagic ascites due to biventricular congestive heart failure in which workup for other causes was negative and hemorrhage cleared after 4 months. In as much as the mechanism of ascites is similar in both cirrhosis and CHF, we propose that a similar mechanism could cause bleeding into ascites in CHF.     

Usefulness of echocardiographic determined tricuspid regurgitation in predicting event-free survival in severe heart failure secondary to idiopathic-dilated cardiomyopathy or to ischemic cardiomyopathy

Two-dimensional and color Doppler echocardiograms obtained in 117 patients during cardiac transplantation evaluation were reviewed. Right ventricular hypokinesia and dilation were more prevalent in patients with tricuspid regurgitation. In multivariate event-free survival analysis of 61 patients with complete clinical, echocardiographic, and cardiopulmonary exercise data, the absence of tricuspid regurgitation and New York Heart Association class were the only independent predictors of survival.