Computational comparison of aortic root stresses in presence of stentless and stented aortic valve bio-prostheses.

We provide a computational comparison of the performance of stentless and stented aortic prostheses, in terms of aortic root displacements and internal stresses. To this aim, we consider three real patients; for each of them, we draw the two prostheses configurations, which are characterized by different mechanical properties and we also consider the native configuration. For each of these scenarios, we solve the fluid-structure interaction problem arising between blood and aortic root, through Finite Elements. In particular, the Arbitrary Lagrangian-Eulerian formulation is used for the numerical solution of the fluid-dynamic equations and a hyperelastic material model is adopted to predict the mechanical response of the aortic wall and the two prostheses. The computational results are analyzed in terms of aortic flow, internal wall stresses and aortic wall/prosthesis displacements; a quantitative comparison of the mechanical behavior of the three scenarios is reported. The numerical results highlight a good agreement between stentless and native displacements and internal wall stresses, whereas higher/non-physiological stresses are found for the stented case.

[Cirrhotic cardiomyopathy: a brief overview]. / La cardiomyopathie du cirrhotique: un bref apercu.

Even though cardiac disorders were described in alcoholic cirrhosis more than fifty years ago, cirrhotic cardiomyopathy was not defined until the end of the eighties. The term is used to describe all the cardiac structural and functional abnormalities observed in cirrhotic patients without any underlying cardiac disease. This cardiomyopathy is characterized by impaired systolic function, often unmasked during stress, diastolic dysfunction, and electrophysiological abnormalities. It can be detected by the electrocardiogram, transthoracic echocardiography and measurements of cardiac biomarkers (BNP). The pathophysiological mechanisms underlying this disease are complex: anomalies of adrenergic transduction pathways, alterations of myocyte membrane fluidity, fibrosis, cardiac hypertrophy, hormonal disturbances, and various ion channels derangements. To date, there is no specific treatment. Liver transplantation may be curative. The possibility of such a condition must be taken into account, when a TIPS or a liver transplantation are considered.

[Heart failure in the elderly]. / L'insuffisance cardiaque du sujet âgé.

Heart failure in the elderly represents a major public health problem.In this population, the general objective of therapy, defined by current guidelines, does not differ from that proposed for younger patients: the aims are to decrease symptoms, to improve quality of life, to decrease hospitalizations, and to increase survival. However, in this category of patients, respect for autonomy and quality of life remains a priority, and requires a personalized approach because of the geriatric characteristics of many patients.