Iris Schuster

Université de Montpellier | UM1 · Gard - France

Introduction Prolonged strenuous exercise can transiently decrease cardiac function. Other studies have identified three major exercise-induced pulmonary changes: bronchoconstriction, dynamic hyperinflation and pulmonary oedema with reduced alveolar–capillary membrane diffusing capacity. This study investigated whether athletes with one of these pu...

Purpose: Despite potential severe cardiac side effects, anabolic androgenic steroids (AAS) are increasingly used by strength athletes. However, previous echocardiographic studies focused on the left ventricular strains (LV) but did not assess LV twist and untwist mechanics. Moreover, LA function has been often neglected, and its stiffness, an impo...

Background: Left ventricular (LV) remodeling, characterized by increased LV hypertrophy and depressed function, is observed in strength-trained athletes who use anabolic-androgenic steroids (AAS). Previous studies reported an increase in cardiac fibrosis in these athletes, which could promote intraventricular dyssynchrony. In this context, this st...

Introduction Early detection of preclinical left ventricular (LV) dysfunction in type 2 diabetic (T2D) patients is crucial because of its associated increased cardiovascular morbidity and mortality. Objective The aim of this study was to: – identify the most sensitive and clinically relevant echocardiographic variables in order to detect early lef...

Introduction It is well-known that bodybuilders (BB) using anabolic androgenic steroids (AAS) showed a majored concentric hypertrophy with an increase of cardiac fibrosis. Some studies demonstrated that cardiac fibrosis may altered electrical conduction and so promote intraventricular dyssynchrony. However, any study evaluated this dyssynchrony in...

Purpose: At the onset of physical exercise, oxygen (O2) transport adapts to meet the working muscle O2 demands. Cardiac output abruptly increases through the concomitant changes of heart rate and stroke volume (SV), which is conditioned by the left ventricular (LV) function. The purpose of this study was to investigate the contribution of many LV...

Contexte : À l’Université de Montpellier, l’enseignement de la physiologie passe par une initiation à la démarche expérimentale, effectuée sous forme d’un apprentissage par problème (APP) au cours d’enseignements dirigés (ED) ou travaux pratiques (TP). Actuellement, les ED/TP de physiologie en 2 e année de Diplôme de formation générale en sciences...

Introduction This study aimed to evaluate the effect of bodybuilding (a combination of training and anabolic steroids abuse) on left ventricular diastolic function and, more specifically, on underlying mechanisms that characterize this function (e.g. filling pressure, relaxation and twist-untwist mechanics). Methods Participants (n = 44; aged 20 t...

Objective: With an aging population and the increasing prevalence of heart failure with preserved ejection fraction, developing strategies to prevent diastolic dysfunction is crucial. Regular endurance training has been suggested to be one such strategy. However, the underlying mechanisms of training, including the effect on left ventricular (LV)...

Background: Noninvasive blood pressure (BP) measurement is essential for the study of human physiology but automatic oscillometric devices only estimate SBP and DBP using various, undisclosed algorithms, precluding standardization and interchangeability. We propose a novel approach by tracking, during pneumatic cuff deflation, the time interval fr...

Aims: The aim of this study was to analyze the temporal relationships between pressure, flow, and Korotkoff sounds, providing clues for their comprehensive interpretation. Materials and methods: When measuring blood pressure in a group of 23 volunteers, we used duplex Doppler ultrasonography to assess, under the arm-cuff, the brachial artery flo...

Objective: The aim of this study was to comprehensively investigate left atrial (LA) reservoir, conduit, and booster pump functions, as well as their predictors in patients with primary systemic arterial hypertension (HTN) and left ventricular (LV) hypertrophy. Methods: Thirty patients with HTN and LV hypertrophy, but no history of atrial arrhyt...

AIMS: Investigations on the cardiac consequences of mountain ultra-marathon (MUM) > 100h are lacking. The present study assessed the progressive cardiac responses during the world's most challenging MUM (Tor des Geants; Italy; 330km; 24000m of positive elevation change). METHODS AND RESULTS: Resting echocardiographic evaluation of morphology, funct...

Background While prevalence and risk factors of carotid stenosis in acute coronary sydrome (ACS) are under investigated, we evaluated patients admitted in our intensive care unit for an ACS in order to define if a screening of this population would be relevant. Methods Systematic carotid Doppler ultrasound screening was done on 102 consecutive pati...

The auscultatory technique remains the point of reference for the validation of non-invasive blood pressure measurement devices, although the exact origin of the Korotkoff sounds is still debated and comparison with intra-arterial measurement shows limits and pitfalls. Automatic oscillometric devices are now widely used by nurses, physicians, and p...

Background: Estrogen receptor beta (ERβ) activation has been shown to be cardioprotective, but the involved cell types and mechanisms are not understood. To investigate whether ERβ restricted to cardiomyocytes contributes to observed cardioprotection, we tested the effects of a cardiomyocyte-specific ERβ overexpression (ERβ-OE) on survival, cardia...

Real-time monitoring of radiofrequency (RF) ablation remains challenging. We used intravascular ultrasound (IVUS) to describe atrial wall changes during RF ablation, and assess the extent of RF-induced lesions. In nine piglets, RF and IVUS catheters were coupled and introduced into the right atrium (RA). RF applications were performed along the int...

In this 69 year-old male patient admitted in the emergency ward because of two consecutive amnesic ictus (with anterograde and retrograde amnesia, temporal and spatial disorientation, without confusion), duplex Doppler examination revealed no carotid or vertebral artery morphological or hemodynamic abnormality, and X-Ray scanner with contrast injec...

Définition de la récidive (Littré) « Réapparition d’une maladie après le rétablissement complet de la santé, au bout d’un laps de temps indéfini qui quelquefois se compte par années ». En médecine vasculaire, la récidive se décline aussi bien pour les artères (récidive d’une sténose préalablement traitée, récidive d’un accident ischémique) que pour...

L’arrivée sur le marché des nouveaux anticoagulants oraux directs (AOD) a fait resurgir un mythe très ancien, celui de l’antidote. L’antidote est selon la définition initiale une substance ou un élément chimique, capable de guérir une personne d’un poison (exemple : le venin de serpent). On peut trouver tous les antidotes dans les centres antipoiso...

Les AVK utilises depuis plus de 50 ans dans le traitement de la maladie thromboembolique veineuse (MTEV) et de la fibrillation atriale sont a l’origine, comment ne pas l’ignorer, de 5000 deces par an (et ce malgre l’existence d’un antidote…). On sait que le risque hemorragique augmente avec l’âge et avec l’existence de facteurs associes de co-morb...

Les troubles neurologiques sont des complications rares de la sclérothérapie à la mousse. Les troubles visuels et les céphalées sont les plus fréquemment rapportés et correspondraient à une aura migraineuse. Exceptionnellement, des accidents ischémiques transitoires et des infarctus cérébraux ont été rapportés. Le fibroélastome papillaire est une t...

Neurological disorders are rare complications of foam sclerotherapy. Visual disturbances and headache are the most commonly reported events and are thought to be equivalent to migraine with aura. Exceptionally, strokes have been reported. Papillary fibroelastoma is a rare cardiac tumor, which may embolize in cerebral arteries. We report the case of...

En 2012 et 2013, à l’initiative de la SFMV a été mise en place l’opération VESALE. Il s’agissait de réaliser un dépistage échographique de l’anévrysme de l’aorte abdominale. Ces opérations ont rassemblé 12 000 personnes, elles ont été réalisées sur une journée. Les critères retenus pour VESALE étaient ceux de la SFMV en 2012 et 2013 0005, 0010 and...

Le dépistage de certaines affections vasculaires est aujourd’hui du domaine des ultrasons. Voici ce qui est validé en 2014 : dépistage de l’anévrysme de l’aorte abdominale (échoscopie ou échographie), la mesure de l’index de pression de cheville pour le dépistage de l’artériopathie asymptomatique. On peut étendre le dépistage au « balayage carotidi...

Background: The aim of this study was to test the effect of endurance training on the age-related changes of left ventricular (LV) twist-untwist mechanics. Aging has been shown to induce a decline of diastolic function and more recently an impairment of twist-untwist mechanics, which constitutes an important factor for early diastolic suction and...

In adults, left ventricular (LV) systolic twist is an important factor that determines LV filling, both at rest and during exercise. In children, lower LV twist has been demonstrated at rest, but its adaptation during exercise and its functional consequences on LV filling are unknown. Using speckle-tracking echocardiography, LV twist-untwist mechan...

Introduction: Prolonged and strenuous exercise (PSE) induces transient left ventricular (LV) dysfunction. Although a consensus exists regarding the decrease in diastolic function, the existence of a decrease in systolic function by a PSE remains controversial, probably due to the transient tachycardia and changes in loading conditions observed upo...

Abnormal left ventricular (LV) deformational mechanics have been demonstrated in patients with hypertrophic cardiomyopathy (HCM) at rest, but there is a lack of information on their adaptation to exercise. The aim of this study was to assess the adaptability of LV strains and torsional mechanics during exercise in HCM patients. Twenty nonobstructiv...

The aim of this study was to evaluate the impact of a low-intensity training program on subclinical cardiac dysfunction and on dyssynchrony in moderately obese middle aged men. Ten obese and 14 age-matched normal-weight men (BMI: 33.6 ± 1.0 and 24.2 ± 0.5 kg/m(2)) were included. Obese men participated in an 8-week low-intensity training program wit...

The dynamics of systolic and diastolic strains and torsional mechanics of the left ventricle (LV) and their relation to diastolic filling never have been evaluated at various exercise intensities. Speckle tracking echocardiography was performed in 20 healthy sedentary subjects at rest and during a progressive submaximal exercise test at 20%, 30%, a...

L'examen ultrasonographique des artères du cou a pour principale fonction de rechercher la présence de lésions athéromateuses et d'identifier les sténoses carotidiennes réduisant de plus de 70 % le diamètre de la carotide interne, ces sténoses représentant les principales indications actuelles de l'endartériectomie chez les patients symptomatiques....

Numerous studies have reported evidence of cardiac injury associated with transient left ventricular (LV) systolic and diastolic dysfunction after prolonged and strenuous exercise. We used 2D ultrasound speckle tracking imaging to evaluate the effect of an ultralong-duration exercise on LV regional strains and torsion. We speculated that systolic d...

The purpose of the study was to evaluate the dynamics of diastolic and systolic function from rest to maximal exercise using conventional echocardiography and tissue Doppler imaging (TDI) in obese prepubertal boys compared to age-matched lean controls. Eighteen obese (10 with first degree obesity and 8 with second degree obesity according to French...

Obese children exhibit vascular disorders at rest depending on their pubertal status, degree of obesity, and level of insulin resistance. However, data regarding their vascular function during exercise remain scarce. The aims of the present study were to evaluate vascular morphology and function at rest, and lower limb blood flow during exercise, i...

Resting and exercise cardiac function, skeletal muscle oxygenation and whole-body aerobic exercise capacities were evaluated prospectively in cardiac symptom-free HIV men receiving antiretroviral therapies and in healthy controls matched for age, physical activity, smoking and body surface area. HIV patients showed resting cardiac dysfunction, alte...

The contraction of cardiomyocytes induces a systolic increase in left ventricular (LV) normal (radial, circumferential and longitudinal) and shear strains, whose functional consequences have not been evaluated, so far, in athletes. We used 2D ultrasound speckle tracking imaging (STI) to evaluate LV regional strain in high-level cyclists compared to...

Although cardiotoxic effects of highly active antiretroviral therapy (HAART) are a growing concern, there is a lack of prospective studies of subclinical involvement of the heart in human immunodeficiency virus (HIV)-infected patients. This study evaluated noninvasively cardiac morphologic characteristics and function in HIV-positive (HIV(+)) men r...

L'ultrasonographie vasculaire continue à bénéficier, année après année, de nombreuses et importantes innovations technologiques. Si l'échographie apporte surtout des renseignements morphologiques, tandis que les données fonctionnelles sont principalement fournies par l'effet Doppler à émission continue ou pulsée, de nouveaux modes de construction d...

Cardiovascular disease is the leading cause of death in the diabetic population. However, molecular mechanisms underlying diabetic cardiomyopathy remain unclear. We analyzed Ca2+-induced Ca2+ release and excitation-contraction coupling in db/db obese type 2 diabetic mice and their control littermates. Echocardiography showed a systolic dysfunction...

To compare the incidence of diastolic and systolic asynchrony, assessed by tissue Doppler imaging (TDI), in patients with congestive heart failure (CHF) and severe left ventricular (LV) dysfunction, and to assess TDI changes induced by cardiac resynchronization therapy (CRT). Thirty percent of CRT candidates are nonresponders. Besides QRS width, th...

This study sought to investigate the relative load dependence of left atrial appendage (LAA) tissue Doppler velocities in patients with mitral stenosis after percutaneous mechanical mitral commissurotomy (PMMC). LAA tissue Doppler velocities were obtained in 34 patients with mitral stenosis (20 with sinus rhythm and 14 with atrial fibrillation) bef...

L’examen des axes carotidiens, dans le cadre de la pathologie cérébrale présumée ischémique, est, de facto, à la fois l’examen de dépistage et de bilan hémodynamique, voire, le cas échéant, l’examen préopératoire. Il doit donc être capable de mettre en évidence la ou les lésions susceptibles de porter une responsabilité étiologique, de les caractér...

Ryanodine receptors/Ca2+-release channels (RyR2) from the sarcoplasmic reticulum (SR) provide the Ca2+ required for contraction at each cardiac twitch. RyR2 are regulated by a variety of proteins, including the immunophilin FK506 binding protein (FKBP12.6). FKBP12.6 seems to be important for coupled gating of RyR2 and its deficit and alteration may...