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

Blood flow in the microcirculation is regulated by physiological oxygen (O2) gradients that are coupled to vasoconstriction or vasodilation, the domain of nitric oxide (NO) bioactivity. The mechanism by which the O2 content of blood elicits NO signaling to regulate blood flow, however, is a major unanswered question in vascular biology. While the hemoglobin in red blood cells (RBCs) would appear to be an ideal sensor, conventional wisdom about its chemistry with NO poses a problem for understanding how it could elicit vasodilation. Experiments from several laboratories have, nevertheless, very recently established that RBCs provide a novel NO vasodilator activity in which hemoglobin acts as an O2 sensor and O2-responsive NO signal transducer, thereby regulating both peripheral and pulmonary vascular tone. This article reviews these studies, together with biochemical studies, that illuminate the complexity and adaptive responsiveness of NO reactions with hemoglobin. Evidence for the pivotal role of S-nitroso (SNO) hemoglobin in mediating this response is discussed. Collectively, the reviewed work sets the stage for a new understanding of RBC-derived relaxing activity in auto-regulation of blood flow and O2 delivery and of RBC dysfunction in disorders characterized by tissue O2 deficits, such as sickle cell disease, sepsis, diabetes, and heart failure.
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PMID:Chemical physiology of blood flow regulation by red blood cells: the role of nitric oxide and S-nitrosohemoglobin. 1570 54

Regarding cardiac failure, the year 2004 was notable for the dissemination of indications for the use of medical devices in heart failure: indications for cardioversion with the long awaited publication of the COMPANION study, advancement of the concept of intra-ventricular asynchronism, and studies of defibrillators in non-ischaemic cardiac failure (COMPANION, DEFINITE, SCD-HeFT, TOVA). Furthermore, pragmatic clinical studies allowed refinement of the uses of BNP (diagnostic and prognostic), underlining the importance of renal function and its progression during hospitalisation, and the risks of using strong, modern therapy in populations without "ad hoc" surveillance which do not correspond with study populations (aldactone in Canada). Just as in coronary patients, it appears to be important to commence full medical treatment prior to hospital discharge, because treatment is rarely changed thereafter. The management of seriously ill patients is evolving with several therapeutic advances: the methods of selecting patients for heart transplants have changed, with the advancement of opportunities for circulatory assistance. Attention has also been turned to the significant group, still poorly understood, of patients with diastolic heart failure, for whom diagnostic methods have been defined, as well as their clinical characteristics. Lastly the medication studies: new drugs in acute cardiac failure (preliminary results for vasopressin antagonists), wider indications for betablockers in elderly subjects (SENIORS), and advances in cellular cardiomyoplasty (using haemopoietic stem cells especially this year). It has been a fruitful year, difficult to summarise in a few lines, or even several pages....
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PMID:[The best of cardiac failure in 2004]. 1571 60

The Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) and the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) have established that patients with a reduced ejection fraction gain an overall mortality benefit from prophylactic implantable cardioverter-defibrillator therapy. Only a small proportion of the patients in these studies, however, have received life-saving therapy from the defibrillator. Because defibrillator therapy is invasive and expensive, patients with a low ejection fraction would benefit from effective risk stratification so that defibrillator therapy was used only in those at significant risk. In this review, we analyze prospective clinical trials that have evaluated microvolt T-wave alternans (MTWA) testing as a predictor of ventricular tachyarrhythmic events in populations of patients similar to those studied in MADIT II or SCD-HeFT; that is, patients with a reduced ejection fraction who were not selected on the basis of a history of ventricular tachyarrhythmias. In these studies, the average annual rate of fatal and nonfatal ventricular tachyarrhythmic events among the patients who tested negative for MTWA was around 1%. This rate is so low that it is unlikely that such patients would benefit from implantable cardioverter-defibrillator therapy. The mortality, moreover, was lower among MTWA-negative patients who did not receive implantable defibrillators than that observed in the MADIT II and SCD-HeFT patients who received implantable cardioverter-defibrillators. In response, patients with a low ejection fraction who are being considered for implantable cardioverter-defibrillator therapy should undergo MTWA testing as part of their evaluation.
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PMID:Can microvolt T-wave alternans testing reduce unnecessary defibrillator implantation? 1618 50

The objective of this work was to assess the frequency the nature of complications and prognosis of the disease in children suffering from sickle cell disease. This retrospective study was conducted from January 2002 to December 2003 among 251 children suffering from sickle cell disease, hospitalized at the Brazzaville Teaching Hospital, Congo. The main hospitalization causes were dominated by the vaso-occlusive crisis (26.7%), anaemic crisis (20.3%) and infections (36.6%). The vaso-occlusive crisis were observed particularly in the 5 year-old children (p < 0.05); the hand-foot syndrome concerned in particular children under 5 years old. Anaemic crisis were found almost exclusively in patients under 5 (p < 0.05). The infections in children under 5 (35.8%) were almost as frequent as in older children (37.4%). Some non infectious complications were only observed in children above 5: cholithiasis, 4 cases; heart failure, 4 cases; hip osteonecrosis, 1 case. Global mortality was 4.8% and higher in children under five (p > 0.05). In addition, the death causes were dominated by anaemic crisis. In conclusion, this study stresses on the need to implement a primary prevention as well as a secondary prevention adapted to age.
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PMID:[Effects of age on causes of hospitalization in children suffering from sickle cell disease]. 1642 22

Primary and secondary prevention of sudden cardiac death is not sufficiently assured by medication. The (automatic) implantable cardioverter/defibrillator ((A)ICD) is able to terminate life-threatening arrhythmias (ventricular fibrillation/flutter, ventricular tachycardia) reliably. The identification and care of risk patients is of crucial importance. Initially, only survived resuscitation for ventricular fibrillation or ventricular tachycardia was regarded as a confirmed indication. Several studies (CABG patch, MADIT, MADIT II, MUSTT, DINAMIT, CAT AMIOVIRT, DEFINITE, COMPANION, SCD-HeFT) have examined the prophylactic indication for ICD therapy in risk groups. Patients with chronic state after myocardial infarction with markedly impaired left ventricular function and/or spontaneous, non-sustained ventricular tachycardia have been documented to benefit. Patients with moderately severe or severe heart failure also profit from ICD implantation, where appropriate in combination with cardiac resynchronization therapy in conduction disorders. There is divergent data on dilated cardiomyopathy. ICD is not indicated in patients with acute infarctions or undergoing elective bypass surgery.
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PMID:AICD treatment in 2004--state of the art. 1710 77

The guidelines for the implantation of cardioverter defibrillators recommend the primary prevention of sudden cardiac death based on the results of MADIT II, Companion and SCD-HeFT. The main risk factors for ventricular arrhythmias are previous myocardial infarction, depressed left ventricular function, and chronic heart failure. The presented case reports demonstrate the indication for a defibrillator or biventricular defibrillator as a basis of clinical pathways.
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PMID:[Sudden cardiac death, ICD and resynchronization therapy]. 1718 Jun 48

Heart failure (HF) is a common and lethal syndrome. Those with moderate left ventricular dysfunction have a substantial risk of premature and sudden death, approximately 25% over 2.5 years. Fifty percent of these deaths are thought to be sudden due to dysrhythmias, which may be preventable. As a consequence, patients with HF represent the largest, single identifiable population of patients that can be targeted for primary prevention of sudden cardiac death. A trial known as SCD-HeFT (The Sudden Cardiac Death in Heart Failure Trial), sponsored by the National Heart Lung and Blood Institute of the National Institutes of Health, was designed to evaluate the value of the prophylactic amiodarone or implantable cardioverter defibrillator therapy in patients with HF. This article reviews 4 key clinical insights highlighted by the SCD-HeFT results: (1) ramifications of implantable cardioverter defibrillator use in patients with New York Heart Association (NYHA) class II HF; (2) the value or lack thereof of implantable cardioverter defibrillator therapy in patients with NYHA class III HF; (3) the danger of amiodarone drug therapy in patients with NYHA class III HF; and (4) the significant value of basic medical management, when well implemented, in prolonging life in this population. In addition, future directions in the evaluation and management of patients with moderate to severe HF are addressed.
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PMID:Key clinical insights from the sudden cardiac death in heart failure trial. 1729 36

This article is going to be somewhat different than the typical article you might read on the treatment of heart failure. My goal is to get you to think in a different way about the use of primary prevention implantable cardioverter defibrillators and beta-blockers in patients with left ventricular dysfunction. Specifically, using the results from 3 landmark clinical trials--MADIT II, SCD-HeFT, and COMET--I am going to discuss the economic, ethical, and legal principles that underpin the use of these 2 therapies in patients with heart failure.
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PMID:Implantable defibrillators and beta-blockers in patients with left ventricular dysfunction: economic, ethical, and legal considerations. 1821 79

A 23-month-old girl presented with heart failure from extremely severe sickle cell anemia. The family refused blood transfusion on religious grounds (Jehovah's Witness). Alternative options acceptable to this religion, such as iron, erythropoietin, or folic acid were rejected as useless in the particular situation of the child. The patient was transfused with Hemopure, a product that consists of polymerized bovine hemoglobin. This is the first case reported in the literature of a child transfused, in an emergency situation, with this product.
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PMID:Hemopure transfusion in a child with severe anemia. 1771 Jun 65

Sudden cardiac death prematurely claims the lives of some 7 million each year worldwide. It occurs primarily in patients with an underlying structural cardiac abnormality, and regardless of the type of the underlying pathology (heart failure, dilated and hypertrophic cardiomyopathies, myocardial infarction and aging), death is almost always caused by ventricular tachycardia (VT) which rapidly degenerates to ventricular fibrillation (VF). Implantable cardioverter defibrillator is an effective but expensive therapy for preventing SCD, and finding a reasonably specific, sensitive and cost-effective risk stratification tool for patients at high risk of sudden cardiac death will have great clinical utility in preventing premature sudden cardiac death. Increased myocardial fibrosis has been shown to develop in a wide range of cardiac diseases all manifesting increased risk of VT and VF. Clinical and experimental studies attribute a major role for fibrosis in the initiation of VT, VF and sudden cardiac death. Transforming growth factor-beta1 (TGF-beta1) has been shown to promote myocardial tissue fibrosis and perhaps more importantly in cardiac conditions associated with increased myocardial fibrosis are shown to be positively correlated with increased serum levels of TGF-beta1. In the present hypothesis we suggest that monitoring the serum levels of TGF-beta1 may be a cost-effective risk stratifier to identify patients at high risk of sudden cardiac death caused by VT and VF.
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PMID:Serum transforming growth factor-beta1 as a risk stratifier of sudden cardiac death. 1844 60


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