Inert gas Narcosis

info:eu-repo/semantics/publishe

Implication des récepteurs NMDA et GABAa dans le contrôle du système dopaminergique nigro-strié chez le rat soumis à la narcose à l'azote, avant et après des expositions répétées

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocSudocFranceF

Low-Flow, Low-Gradient Severe Aortic Stenosis Despite Normal Ejection Fraction Is Associated With Severe Left Ventricular Dysfunction as Assessed by Speckle-Tracking Echocardiography: A Multicenter Study.

Background- Low-flow low-gradient (LFLG) is sometimes observed in severe aortic stenosis (AS) despite normal ejection fraction, but its frequency and mechanisms are still debated. We aimed to describe the characteristics of patients with LFLG AS and assess the presence of longitudinal left ventricular dysfunction in these patients. Methods and Results- In a multicenter prospective study, 340 consecutive patients with severe AS and normal ejection fraction were studied. Longitudinal left ventricular function was assessed by 2D-strain and global afterload by valvulo-arterial impedance. Patients were classified according to flow and gradient: low flow was defined as a stroke volume index ≤35 mL/m(2), low gradient as a mean gradient ≤40 mm Hg. Most patients (n=258, 75.9%) presented with high-gradient AS, and 82 patients (24.1%) with low-gradient AS. Among the latter, 52 (15.3%) presented with normal flow and low gradient and 30 (8.8%) with LFLG. As compared with normal flow and low gradient, patients with LFLG had more severe AS (aortic valve area=0.7±0.12 cm(2) versus 0.86±0.14 cm(2)), higher valvulo-arterial impedance (5.5±1.1 versus 4±0.8 mm Hg/mL/m(2)), and worse longitudinal left ventricular function (basal longitudinal strain=-11.6±3.4 versus -14.8±3%; P<0.001 for all). Conclusions- LFLG AS is observed in 9% of patients with severe AS and normal ejection fraction and is associated with high global afterload and reduced longitudinal systolic function. Patients with normal-flow low-gradient AS are more frequent and present with less severe AS, normal afterload, and less severe longitudinal dysfunction. Severe left ventricular longitudinal dysfunction is a new explanation to the concept of LFLG AS

Apical four-chamber longitudinal left ventricular strain in patients with aortic stenosis and preserved left ventricular ejection fraction analysis related with flow/gradient pattern and association with outcome

International audienceAims - To evaluate the prognostic value of apical four-chamber (A4-C) longitudinal strain (LS) in patients with aortic stenosis (AS). Methods and results - In a multicentre cohort, 582 patients (74.3 ± 10.9 years) with moderate or severe AS and preserved left ventricular (LV) ejection fraction (≥50%) were included in this retrospective study. Patients with severe AS were classified in four subgroups according to flow and gradient: low flow (LF) was defined as a stroke volume index <35 mL/m2 compared with normal flow (NF); low-gradient (LG) as a mean gradient <40 mmHg compared with high gradient (HG). The end point was all-cause of mortality. A4-C LS was measured by two-dimensional speckle tracking and was feasible in all patients. The degree of A4-C LV longitudinal dysfunction increased according to the severity and subgroups of severe AS: from the least to the most impaired: moderate AS, NF/HG, NF/LG, LF/HG, and LF/LG AS (P < 0.001). During a mean follow-up of 2.6 ± 0.2 years, 58(10%) patients died. The 2-year survival was 76.8% in patients with LF/LG vs. 89.3% in patients with other groups. The best threshold of A4-C LS associated with overall mortality was an absolute cut-off value of |13.75%|. According to this cut-off, the 2-year survival was higher both in patients with moderate AS (96.3 vs. 70%, P = 0.02) and those with severe AS (92.9 vs. 80.9%, P = 0.005). However when dichotomized according to flow/gradient patterns, the association was only statistically significant in the subgroup of patients with NF/HG. By multivariable cox regression analysis, A4-C LS <|13.75| remained independently associated with overall mortality (hazard ratio: 1.8; P = 0.045). Conclusion - A4-C LS is independently associated with death in patients with AS and preserved LVEF, however the flow/gradient pattern should also be considered as an important parameter. The management of these patients may use A4-C LS as a new parameter of evaluation of LV function and prognosis

Whole Exome Sequencing Reveals a Large Genetic Heterogeneity and Revisits the Causes of Hypertrophic Cardiomyopathy

International audienc

Diagnosis of Infective Endocarditis After TAVR

International audienc