Rôle de l'IRM cardiaque dans le dépistage des cardiomyopathies de l'adulte [Cardiomyopathy and cardiac magnetic resonance].

Cardiovascular magnetic resonance (CMR) is a rapidly emerging non-invasive imaging technique free of X-Ray and offers higher spatial resolution than alternative forms of cardiac imaging for the assessment of left ventricular (LV) anatomy, function, and viability due to the unique capability of myocardial tissue characterization after gadolinium-chelates contrast administration. This imaging technique has clinical utility over a broad spectrum of heart diseases: ranging from ischaemic to non ischaemic aetiologies. Cardiomyopathies (CMP) are a heterogeneous group of diseases of the myocardium associated with architectural abnormalities and mechanical dysfunction. CMR can help excluding coronary artery disease and can provide positive diagnostic features for several CMP resulted in better diagnosis and management, Leading to improvements in mortality.

IRM cardiaque dans le suivi des cardiopathies congénitales à l'âge adulte [Cardiac MRI in the follow-up of adult congenital cardiomyopathy patients].

Magnetic resonance imaging is a rapidly developing modality in cardiology. It offers an excellent image definition and a large field of view, allowing a more accurate morphological assessment of cardiac malformations. Due to its unique versatility and its ability to provide myocardial tissue characterization, cardiac magnetic resonance (CMR) is now recognized as a central imaging modality for a wide range of congenital heart diseases, including assessment of post-surgical cardiac anatomy, quantification of valvular disease and detection of myocardial ischemia. CMR provides useful diagnostic information without any radiation exposure, and improves the global management of patients with congenital heart disease.

Effets hémodynamiques d'un inhibiteur de l'effet vasculaire de la vasopressine chez des patients avec insuffisance cardiaque congestive [Hemodynamic effects of an inhibitor of the vascular effects of vasopressin in patients with congestive heart failure]

To assess the role of vasopressin (AVP) in congestive heart failure (CHF), we investigated 10 patients with CHF refractory to conventional treatment, before and 60 minutes after intravenous administration of 5 micrograms/kg of d(CH2)5Tyr(Me)AVP, a specific antagonist of AVP at the vascular receptor level. Heart rate, systemic arterial pressure, pulmonary arterial pressure, pulmonary capillary wedge pressure, cardiac index by thermodilution, and cutaneous blood flow by laser-Doppler technique were measured. In 9 patients there was no significant hemodynamic and cutaneous blood flow response to the AVP antagonist. Plasma AVP was 2.3 +/- 0.8 pg/ml and plasma osmolality 284 +/- 14 mosm/kg H2O. The tenth patient had the most severe CHF. His plasma AVP was 55 pg/ml and plasma osmolality 290 mosm/kg. He responded to the AVP antagonist with a marked decrease in systemic arterial pressure from 115/61 to 79/41 mm Hg, in pulmonary arterial pressure from 58/31 to 33/13 mm Hg and in pulmonary capillary wedge pressure from 28 to 15 mm Hg. Simultaneously cardiac index increased from 1.1 to 2.21 X min-1 X m-2 and cutaneous blood flow rose 5-fold. Thus, most patients with CHF have only moderately elevated plasma AVP and its role in determining peripheral vascular resistance appears to be limited. AVP may become important in rare patients presenting with marked hemodynamic instability and very high plasma AVP.

Evaluation cardiologique préopératoire avant chirurgie non cardiaque: stratification du risque cardiovasculaire [Preoperative cardiac assessment before non-cardiac surgery: cardiac risk stratification].

Perioperative cardiac events occurring in patients undergoing non-cardiac surgery are a common cause of morbidity and mortality. Current guidelines recommend an individualized approach to preoperative cardiac risk stratification prior to non-cardiac surgery, integrating risk factors both for the patient (active cardiac conditions, clinical risk factors, functional capacity) and for the planned surgery. Preoperative cardiac investigations are currently limited to high-risk patients in whom they may contribute to modify the perioperative management. A multidisciplinary approach to such patients, integrating the general practitioner, is recommended in order to define an individualized peri-operative strategy.

Suivi du patient après transplantation cardiaque: monitoring et adaptation de l'immunosuppression [Monitoring and adjustment of immunosuppression after heart transplantation].

Heart transplantation remains the best therapeutic option for the treatment of end-stage heart failure. However, good survival rates can be obtained only if patients are closely monitored, particularly for their immunosuppressive regimens. Currently, a triple-drug regimen usually based on calcineurin-inhibitors (cyclosporin A or tacrolimus), anti-proliferative agents and steroids is used in most recipients. New agents such as the mTOR inhibitors, a more recently developed class of immunosuppressive drugs, can also be used in some patients. The aim of this article is to review currently used immunosuppressive regimens after heart transplantation, and to propose some individualized options depending on specific patient characteristics and recent pharmacological developments in the field.

La fonction rénale sous inhibition de l'enzyme de conversion de l'angiotensine [Renal function after administration of angiotensin-converting enzyme inhibitors]

Angiotensin converting enzyme (ACE) inhibitors are widely used today for the management of hypertension and congestive heart failure. These agents inhibit angiotensin II synthesis. In some particular circumstances they may be responsible for deterioration of renal function, e.g. in hypertensive patients with bilateral renal artery stenosis or with stenosis of the artery supplying a single kidney, or in patients with severe congestive heart failure or marked nephroangiosclerosis. In these patients renal perfusion pressure may become too low to maintain adequate glomerular filtration as there remains no angiotensin II to increase the tone of the efferent arteriole. In high risk patients it is therefore recommended that serum creatinine be checked after initiating therapy with an ACE inhibitor.

Prédiction des durées de séjour en réadaptation en fonction du statut fonctionnel. [Usefulness of functional status to predict length of stay in rehabilitation.]

Objectif : En Suisse, la réadaptation est financée en¦partie par l'assureur qui fixe préalablement à l'admission¦un nombre de jours (durée garantie) qu'il s'engage¦à rembourser. Lorsqu'une durée garantie est trop courte,¦une demande de prolongation est nécessaire, induisant¦des démarches administratives. Les objectifs de cette¦étude étaient a) d'étudier le lien entre durées garanties¦et caractéristiques du patient ; b) d'estimer les coûts¦liés aux demandes de prolongation ; c) d'évaluer¦l'impact de l'introduction d'un modèle d'attribution de¦durée garantie basé sur l'état fonctionnel du patient.¦Méthodes : Les corrélations entre état fonctionnel,¦durée effective et durée garantie ont été testées sur¦208 séjours représentatifs. Des durées garanties fictives¦ont été calculées à partir de la médiane de durée de¦séjour de 2 335 patients, groupés selon leur niveau¦fonctionnel (score des activités de base de la vie quotidienne¦(BAVQ) 0-1 vs 2-4 vs 5-6), puis comparées aux¦durées de séjour effectives et garanties.¦Résultats : L'état fonctionnel du patient n'est pas¦corrélé à la durée garantie, et 69 % des séjours nécessitent¦au moins une demande de prolongation, représentant¦2,6 équivalents temps plein en temps administratif¦projeté sur le canton. L'application du modèle proposé¦réduirait de 28 % les demandes de prolongation, et¦n'augmenterait que marginalement la proportion de¦jours garantis en surplus (11,2 % contre 6,5 % actuellement).¦Conclusion : L'utilisation systématique d'un modèle¦d'attribution de durées garanties basées sur l'état¦fonctionnel du patient permettrait de réduire sensiblement¦les coûts administratifs liés aux demandes de¦prolongation, sans entraîner de risque accru d'une augmentation¦de la durée de séjour.

Deux extensions de Théorèmes de Hamburger (portant sur l'équation fonctionnelle de la fonction dzêta)

We propose two types of extensions to Hamburger’s theorems on the Dirichlet series with functional equation like the one of the Riemann zeta function, under weaker hypotheses. This builds upon the dictionary betweeen the moderate meromorphic functions with functional equation and the tempered distributions with extended S-support condition.

Prothèses totales d'épaules inversées : récupérer la fonction en cas d'incompétence de la coiffe des rotateurs

Les principales caractéristiques biomécaniques de la prothèse inversée (cupule sur le versant huméral et sphère sur le versant scapulaire), cet implant semi-contraint, consistent en une médialisation ainsi qu'un abaissement du centre de rotation. Par ce biais, le bras de levier du deltoïde est augmenté. Les fibres musculaires du deltoïde antérieur et postérieur sont ainsi également recrutées pour devenir principalement abducteur. La congruence relative des composants (semi-contrainte) confère également à la prothèse inversée une certaine stabilité primaire, importante pour pallier la déficience de la coiffe des rotateurs (sus-épineux).

Assistances ventriculaires gauches dans le choc cardiogène et l'insuffisance cardiaque terminate [Left ventricular assist devices in cardiogenic shock and chronic refractory heart failure].

Decompensated heart failure, either acute (cardiogenic shock) or chronic (terminal heart failure) may become refractory to conventional therapy, then requiring mechanical assistance of the failing heart to improve hemodynamics. In the acute setting, aortic balloon counterpulsation is used as first line therapy. In case of failure, other techniques include the extracorporal membrane oxygenator or a percutaneous left ventricular assist device, such as the TandemHeart or the Impella. In chronic heart failure, long-term left ventricular assist devices can be surgically implanted. The continuous flow devices give here the best results. The aim of the present review article is to present with some details the various methods of mechanical left ventricle assistance to which the intensivist may be confronted in his daily practice.