Heart failure monitor最新文献

Chronic heart failure (CHF) is a leading cause of morbidity and mortality. Although a precise definition for a cut-off value of hemoglobin level for anemia is still lacking, it has recently been found to be a common complication in CHF, occurring in 10-20% of patients. There are several possible pathogenetic mechanisms for anemia in CHF, and a precise underlying cause is found in only a minority of patients. In CHF, more than 50% of anemia cases are considered to be 'anemia in chronic illness'. In CHF patients, low hemoglobin values directly relate to poor peak oxygen consumption, disabling symptoms, and impaired survival. Recent pilot studies showed that correction of anemia with erythropoietin and iron may lead to improvement in symptoms and exercise capacity. These issues need to be tested in larger, double-blind, randomized, placebo-controlled trials before anemia treatment becomes routine in patients with CHF.

Congestive heart failure (CHF) is a disease condition that is increasing in prevalence and is associated with significant morbidity and mortality. Left ventricular systolic dysfunction (LVSD) is a treatable precursor of CHF, but remains asymptomatic in about half of the individuals afflicted. This observation has spurred interest in screening for LVSD. Plasma B-type natriuretic peptide (BNP) is a widely accepted test for the diagnosis of overt CHF. In this review, we examine the potential role for plasma BNP as a screening tool for asymptomatic LVSD. The performance of any screening test depends on its accuracy, the prevalence of the disease condition screened for, and the availability of resources for follow-up of individuals in whom the disease was detected. In the context of community-wide screening for LVSD, a test with high specificity would be important so as to minimize the costs of expensive definitive follow-up tests (i.e. echocardiography). The prevalence of significant LVSD (ejection fraction 20.40) is low, limiting the enthusiasm for a screening program targeting the general population. This is especially true for women, in whom the condition is rare, and the performance characteristics of plasma BNP are sub-optimal. In men, plasma BNP may be a useful screening test in high-risk individuals in whom there are no other clinical indications for echocardiography. The choice of the appropriate plasma BNP threshold that triggers further work-up in such high-risk individuals may vary according to the availability of resources, and with the healthcare priorities of a community.

Persistence of cardiotropic viruses (enterovirus, adenovirus) and anticardiac autoimmunity constitute the predominant etiopathogenic pathways of dilated cardiomyopathy (DCM). The diagnosis of inflammatory cardiomyopathy (InfCM) imposes sensitivity and specificity requirements, which are not fulfilled by the histological Dallas Criteria. The immunohistological quantification and characterization of immunocompetent infiltrates and cell adhesion molecule (CAM) expression has endorsed a new entity of secondary cardiomyopathies acknowledged by the World Health Organization (WHO), InfCM, in approximately 50% of DCM patients. In the absence of viral persistence, InfCM patients benefit from immunosuppressive treatment. Enteroviral and adenoviral genomes have been detected in a significant proportion of DCM patients. Enteroviral persistence is associated with an adverse prognosis. The induction of the coxsackie-adenovirus receptor (CAR) exclusively in 63% of DCM patients, but not in other cardiomyopathies, might constitute a key molecular determinant for cardiotropic viral infections in DCM. In InfCM patients with enterovirus or adenoviral persistence, interferon-beta administration leads to viral elimination and cessation of the intramyocardial inflammation, paralleled by a significant improvement of left ventricular systolic function and heart failure symptoms. The biopsy-guided etiopathogenic differentiation of DCM has endorsed specific treatment strategies: immunosuppressive regimens are favorable in autoimmune InfCM, whereas patients with viral persistence benefit from antiviral immunomodulation.

Constrictive pericarditis and restrictive cardiomyopathy, two relatively uncommon clinical conditions, create a diagnostic dilemma primarily because of the many similarities in both their clinical and hemodynamic presentations. However, considerable differences exist in the pathophysiology, management, and prognosis between these two syndromes. Furthermore, the precise diagnosis of constrictive pericarditis and restrictive cardiomyopathy is mandatory, as the former is often curable whereas only palliative treatments are available for the latter. In this brief review, similarities and differences in the various aspects of constrictive pericarditis and restrictive cardiomyopathy will be discussed.

There are a number of theoretical reasons as to why 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) should be prescribed to patients with chronic heart failure (CHF). These agents are proven to prevent coronary heart disease, the major etiological factor in the development of CHF. Potential additional effects of these agents include inhibition of proinflammatory cytokine activity and other potential beneficial effects on cardiac remodeling. However, there are also possible adverse effects of this strategy, supported by the overriding observation that low plasma lipid levels portend a poorer prognosis in patients with established CHF. Potential mechanisms by which statins may directly confer adverse effects include a reduction in levels of the antioxidant ubiquinone and an increase in blood endotoxin levels, both of which may contribute to CHF disease progression. Given these uncertainties, an answer to the question of whether or not therapy for CHF should include statins requires a definitive clinical trial. The importance of such a trial is further highlighted by the already commonplace usage of statins amongst patients with CHF.

Beta-adrenergic blocking agents, or beta-blockers, are indicated in the management of angina pectoris, myocardial infarction, hypertension, congestive heart failure (CHF), cardiac arrhythmias, and thyrotoxicosis, and are given to reduce perioperative complications. Despite clear evidence that they reduce morbidity and mortality, clinicians are often hesitant to administer them for fear of adverse reactions. Over the past several years, many of the contraindications traditionally listed for betablockers have been questioned and disproved. Beta-blockers were contraindicated in CHF because of their intrinsic negative inotropic activity, but have now been shown to be beneficial, partly due to their ability to enhance sensitivity to sympathetic stimulation. Beta-blockers have also been contraindicated for patients with obstructive lung diseases, such as asthma and chronic obstructive pulmonary disease, due to the potential risk for bronchospasm. However, new evidence has shown that cardioselective beta-blockers are safe in patients with obstructive lung diseases, and may actually be beneficial by enhancing sensitivity to endogenous or exogenous beta-adrenergic stimulation. This article will review the evidence concerning the safety of beta-blocker use in patients with CHF and concomitant obstructive lung disease, with specific attention to tracking the transition from myth to evidence- based practice.