Biomedical subjects

P Le Corvoisier

Publications and source records attributed to P Le Corvoisier.

8 recordsLinked to original sources

PubMed2005

[Sleep apnoea syndrome and cardiac failure].

Despite recent therapeutic advances, chronic cardiac failure is still associated with a significant morbidity and mortality. Sleep apnoea syndrome is common in this population, affecting almost half of these patients. However, it is rarely diagnosed and treated. There are two types of sleep apnoea syndrome, which can sometimes co-exist: the obstructive apnoea syndrome with collapse of the upper airways, and the central apnoea syndrome with cyclical Cheyne-Stokes respiration, linked with anomalies of central control. Apnoea leads to sympathetic stimulation and an increase in the left ventricular post-charge which can alter cardiac function and the prognosis. Diagnosis of sleep apnoea syndromes is now made with small ambulatory oxymeters which do not disturb sleep and which allow precise detection of episodes of desaturation. Treatment with positive pressure ventilation brings an improvement in daytime symptoms (fatigue, drowsiness) as well as an improvement in cardiac function. Screening for sleep apnoea is thus essential in patients with chronic heart failure, especially in those resistant to optimal drug treatment, in order to improve their management.

Cheyne-Stokes Respiration↗

PubMed2005

Tumor necrosis factor alpha and glutathione interplay in chronic heart failure.

The pro-inflammatory cytokine, tumor necrosis factor alpha (TNF alpha), in concert with neurohormones, contributes to chronic heart failure (CHF) progression. This implies that TNF a antagonism may constitute an important target for CHF therapy. However, clinical trials in CHF patients using compounds that trap TNF alpha, comprising infliximab, an antibody directed to TNF alpha, and etanercept, a soluble recombinant receptor of TNF alpha, gave disappointing results bringing back to light the dual, short-term beneficial and long-term harmful effect of TNF alpha. This review focuses on the dual, concentration- and time-related effects of TNF alpha, the yin and yang action of TNF alpha in cardiac ischemia/reperfusion and contraction. Importantly, the harmful effects of TNF a are related to glutathione deficiency, a common hallmark to several other chronic inflammatory diseases. Recently, in rat models of CHF, oral administration of the glutathione precursor, N-acetylcysteine (NAC), was shown to hinder pathways of TNF alpha harmful signalling and to rescue cardiac structure and function. These results suggest that glutathione deficiency in association with TNF alpha activation may play a role in the pathophysiology of CHF and that NAC may represent a potential therapy in CHF.

Acetylcysteine↗

PubMed2003

[Aldosterone and its antagonists in heart failure].

THE ROLE OF ALDOSTERONE: Aldosterone is the key hormone in salt-water homeostasis. In heart failure, it participates in the appearance and maintenance of signs of congestion. Predominantly synthesised in the glomerular area of the cortico-adrenal glands, extra adrenal production areas have recently been identified notably in the brain, the heart and the large artery trunks. Aldosterone is activated in the cells by the intracellular mineral corticoid receptor. IN CARDIOVASCULAR-PATHOLOGIES: In chronic heart failure, patients treated with conversion enzyme inhibitor may escape from the renin-angiotensin blockade and this may lead to increased aldosterone plasma levels. This increase can induce not only vascular lesions and myocardial fibrosis but also renal and cerebral lesions. THE EFFECTS OF SPIRONOLACTONE: In patients with NYHA stage III or IV heart failure, addition of spironolactone to the treatment with conversion enzyme inhibitor, diuretic and/or digitalis leads to a reduction in morbidity and mortality, as demonstrated in the RALES study. The mechanisms by which spironolactone has a beneficial effect remain discussed. IN CLINICAL PRACTICE: The prescription of spironolactone is limited by hormonal side effects it provokes. IN THE FUTURE: Eplerenone, a new competitive aldosterone receptor antagonist that appears to be devoid of such side effects and which, at least experimentally may well have the same beneficial effects, is presently under clinical assessment.

Adrenergic beta-Antagonists↗

PubMed2003

Impact of genetic polymorphisms on heart failure prognosis.

Recent progress in genomic applications have led to a better understanding of the relationship between genetic background and cardiovascular diseases such as heart failure. The broad variability in heart failure patient outcome is in part secondary to modifier genes, i.e. genes that are not involved in the genesis of a disease but modify the severity of the phenotypic expression once the disease has developed. The strategy most commonly used to identify modifier genes is based on association studies between the severity of the phenotype and the sequence variation(s) of selected candidate gene(s). Using this strategy, several polymorphisms of the beta 1 and beta 2-adrenergic receptors genes and the angiotensin converting enzyme gene have been correlated to the prognosis of patients with heart failure. Recently, we have applied an experimental strategy, known as genome mapping, for the identification of heart failure modifier genes. Genome mapping has previously been used with success to identify the genes involved in the development of both monogenic and multifactorial diseases. We have shown that the prognosis of heart failure mice, induced through calsequestrin overexpression, is linked to two Quantitative Trait Loci localized on chromosomes 2 and 3. Using both strategies (candidate gene and genome mapping) should allow us to identify a number of modifier genes that may provide a more rational approach to identify patients with the worst prognosis and to predict their response to therapy.

AMP Deaminase↗

PubMed2003

Modifier genes and heart failure.

Recent progress in genomic applications have led to a better understanding of the relationship between genetic background and cardiovascular diseases such as heart failure. A considerable component of the variability in heart failure outcome is due to modifier genes, i.e. genes that are not involve in the genesis of a disease but modify the severity of the phenotypic expression once the disease has developed. The strategy most commonly used to identify modifier genes is based on association studies between the severity of the phenotype of the disease (morbidity and/or mortality) and the sequence variation(s) of selected candidate gene(s). This strategy has showed that several polymorphisms of the beta1 and beta2 adrenergic receptors genes and the angiotensin converting enzyme gene are correlated to the prognosis of patients with heart failure. Recently, we have applied an experimental strategy, known as genome mapping, for the identification of heart failure modifier genes. Genome mapping has previously been used with success to identify the genes involved in the development of both monogenic and multifactorial diseases. We have showed that the prognosis of heart failure mice, induced through overexpressing calsequestrin, is linked to 2 Quantitative Trait Loci (QTL) localized on chromosome 2 and 3. Using both strategies (candidate gene and genome mapping) should allow us to identify a number of modifier genes that may provide a more rational approach to identify patients at risk for disease and response to therapy.

Calsequestrin↗

PubMed2002

[Future molecules in heart failure].

TODAY: The management of heart failure (HF) has considerably progressed over the last two decades. Treatment today relies on prevention and treatment of congestion (limited salt intake, diuretics, converting enzyme inhibitors) and limiting neurohormone stimulation (converting enzyme inhibitors +/- aldactone, beta-blockers). IN THE YEARS TO COME: Based on new concepts, several therapeutic strategies are interesting: blocking over vasoconstrictor systems which have not been taking into account; stimulation of vasodilator and natriuretic systems; modulation of cardiac remodelling; modulation of the immune and inflammatory systems; modification in intrinsic contractility; prevention of rhythm disorders. Among these differing strategies and molecules, it is not easy to predict those that will change the HF prognosis. In any event, their efficacy and safety remain to be demonstrated with large cohort randomised studies. THE PRINCIPLES: To reduce the number of drugs administered, two options appear particularly interesting: measurement of hormone levels (BNP) in order to adjust treatment and administration of molecules with greatest efficacy and safety profiles; limit cardiac remodelling by using new imaging techniques to detect it more precisely and select the molecule(s) exerting the required effect. To target the new molecules better, patients should be classified according to their etiology, stage and progressive profile of their disease, cardiac remodelling, expression of principle endocrine systems and pro-inflammatory cytokines, expression of inflammatory and immune systems and inherent genetic characteristics and response to treatment. This would permit the adaptation of treatment to each individual patient with heart failure.

Forecasting↗

PubMed2001

[Hospital mortality in cardiology. Analysis of deaths occurring in the Federation of Cardiology of a university hospital center].

The aim of this study was to examine the nature of cardiovascular deaths occurring in a University Hospital. All the hospital files of 1999 of the Federation of Cardiology of Henri Mondor Hospital, Creteil, of patients who died in the department or after transfer to the intensive care unit or cardiac surgery department, were analysed. Myocardial ischaemia was the leading cause of death, occurring either in the acute phase of transmural infarction or in patients with chronic cardiac failure. Deaths occurring during acute myocardial infarction were associated with late treatment and/or non-reperfusion of the culprit artery. The delay of diagnosis seemed to be secondary to late consultation or difficulty in diagnosis. This resulted in severe left ventricular dysfunction and, in a quarter of cases, mechanical complications. They led to the early death of the patients (2.9 +/- 3.5 days after admission). Campaigns of patient information and education of doctors who see these patients would seem to be the most appropriate approach to reduce the delay before hospital admission in order to reduce mortality related to myocardial infarction. Cardiac failure is a common cause of death in cardiology departments. The deaths of patients occurred after a long follow-up and several days after hospital admission (11 +/- 10 days). Optimisation of the treatment of cardiac failure, the investigation of ischaemic heart disease, the search for new therapeutic strategies of acute cardiac failure and information of patients about their disease, seem to be the principal measures to take to improve the poor prognosis of this disease.

Aged↗

PubMed2000

[Role of nitric oxide in heart failure].

The benefit effects of nitric oxide (NO) donors in acute heart failure have led to the development of vasodilators as treatment of chronic heart failure. However, the mechanisms involved in the effects of NO are complex and still discussed. In chronic heart failure, the eNOS downregulation in vascular endothelium explains the alteration of endothelial function. In addition, in the myocardium, cytokines induce the expression of inducible nitric oxide synthase (iNOS) which increase NO production by myocytes and surrounding cells. This excess of NO production, associated with anion superoxide synthesis, limits the inotropic properties of catecholamines and exert proapoptotic effects. The role of NO donors in heart failure treatment is still controversial but by reducing preload they improve patient's symptoms. Beside blockade of the renin-angiotensin system, the angiotensin converting enzyme inhibitors act via the inhibition of bradykinin degradation which increase NO levels. Finally, vascular endothelial NO expression is improved by exercise training and participates in the improvement of exercise capacity in patients with chronic heart failure involved in cardiac readaptation program.

Animals↗