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1.
ESC Heart Fail ; 9(5): 3101-3112, 2022 10.
Article de Anglais | MEDLINE | ID: mdl-35748123

RÉSUMÉ

AIMS: This study sought to describe and evaluate the impact of a routine in-hospital cardiac resynchronization therapy (CRT) programme, including comprehensive heart failure (HF) evaluation and systematic echo-guided CRT optimization. METHODS AND RESULTS: CRT implanted patients were referred for optimization programme at 3 to 12 months from implantation. The program included clinical and biological status, standardized screening for potential cause of CRT non-response and systematic echo-guided atrioventricular and interventricular delays (AVd and VVd) optimization. Initial CRT-response and improvement at 6 months post-optimization were assessed with a clinical composite score (CCS). Major HF events were tracked during 1 year after optimization. A total of 227 patients were referred for CRT optimization and enrolled (71 ± 11 years old, 77% male, LVEF 30.6 ± 7.9%), of whom 111 (48.9%) were classified as initial non-responders. Left ventricular lead dislodgement was noted in 4 patients (1.8%), and loss or ≤90% biventricular capture in 22 (9.7%), mostly due to arrhythmias. Of the 196 patients (86%) who could undergo echo-guided CRT optimization, 71 (36.2%) required VVd modification and 50/144 (34.7%) AVd modification. At 6 months post-optimization, 34.3% of the initial non-responders were improved according to the CCS, but neither AVd nor VVd echo-guided modification was significantly associated with CCS-improvement. After one-year follow-up, initial non-responders maintained a higher rate of major HF events than initial responders, with no significant difference between AVd/VVd modified or not. CONCLUSIONS: Our study supports the necessity of a close, comprehensive and multidisciplinary follow-up of CRT patients, without arguing for routine use of echo-guided CRT optimization.


Sujet(s)
Thérapie de resynchronisation cardiaque , Défaillance cardiaque , Humains , Mâle , Adulte d'âge moyen , Sujet âgé , Sujet âgé de 80 ans ou plus , Femelle , Thérapie de resynchronisation cardiaque/méthodes , Échocardiographie , Résultat thérapeutique , Dispositifs de resynchronisation cardiaque
2.
Arch Cardiovasc Dis ; 114(11): 748-760, 2021 Nov.
Article de Anglais | MEDLINE | ID: mdl-34627704

RÉSUMÉ

Diabetes mellitus is a metabolic disorder with a chronic hyperglycaemic state. Cardiovascular diseases are the primary cause of mortality in patients with diabetes. Increasing evidence supports the existence of diabetic cardiomyopathy, a cardiac dysfunction with impaired cardiac contraction and relaxation, independent of coronary and/or valvular complications. Diabetic cardiomyopathy can lead to heart failure. Several preclinical and clinical studies have aimed to decipher the underlying mechanisms of diabetic cardiomyopathy. Among all the co-factors, hyperglycaemia seems to play an important role in this pathology. Hyperglycaemia has been shown to alter cardiac metabolism and function through several deleterious mechanisms, such as oxidative stress, inflammation, accumulation of advanced glycated end-products and upregulation of the hexosamine biosynthesis pathway. These mechanisms are responsible for the activation of hypertrophic pathways, epigenetic modifications, mitochondrial dysfunction, cell apoptosis, fibrosis and calcium mishandling, leading to cardiac stiffness, as well as contractile and relaxation dysfunction. This review aims to describe the hyperglycaemic-induced alterations that participate in diabetic cardiomyopathy, and their correlation with the severity of the disease and patient mortality, and to provide an overview of cardiac outcomes of glucose-lowering therapy.


Sujet(s)
Diabète , Cardiomyopathies diabétiques , Défaillance cardiaque , Hyperglycémie , Cardiomyopathies diabétiques/étiologie , Coeur , Humains , Stress oxydatif
5.
Arch Cardiovasc Dis ; 112(10): 630-641, 2019 Oct.
Article de Anglais | MEDLINE | ID: mdl-31494082

RÉSUMÉ

Myocarditis encompasses a wide range of myocardial inflammatory diseases, including acute myocarditis, chronic myocarditis and inflammatory cardiomyopathies, and myocardial inflammation associated with other cardiomyopathies. Because of this heterogeneity in clinical presentation, and the infrequent use of endomyocardial biopsy, cardiac imaging has gradually acquired a key role in the non-invasive detection of myocardial inflammation, the assessment of aetiology and the management of specific therapies. This article summarizes the issue of myocarditis and myocardial inflammation in clinical practice, and reviews the role of different non-invasive imaging techniques in the exploration of myocardial inflammation.


Sujet(s)
Techniques d'imagerie cardiaque , Cardiomyopathies/imagerie diagnostique , Myocardite/imagerie diagnostique , Cardiomyopathies/physiopathologie , Cardiomyopathies/thérapie , Humains , Myocardite/physiopathologie , Myocardite/thérapie , Valeur prédictive des tests , Pronostic , Reproductibilité des résultats
6.
Circ Cardiovasc Imaging ; 12(1): e008122, 2019 12.
Article de Anglais | MEDLINE | ID: mdl-30632389

RÉSUMÉ

BACKGROUND: Assessment of left ventricular (LV) filling pressure is among the important components of a comprehensive echocardiographic report. Previous studies noted wide limits of agreement using 2009 American Society of Echocardiography/European Association of Echocardiography guidelines, but reproducibility of 2016 guidelines update in estimating LV filling pressure is unknown. METHODS: Echocardiographic and hemodynamic data were obtained from 50 patients undergoing cardiac catheterization for clinical indications. Clinical and echocardiographic findings but not invasive hemodynamics were provided to 4 groups of observers, including experienced echocardiographers and cardiology fellows. Invasively acquired LV filling pressure was the gold standard. RESULTS: In group I of 8 experienced echocardiographers from the guidelines writing committee, sensitivity for elevated LV filling pressure was 92% for all observers, and specificity was 93±6%. Fleiss κ-value for the agreement in group I was 0.80. In group II of 4 fellows in training, sensitivity was 91±2%, and specificity was 95±2%. Fleiss κ-value for the agreement in group II was 0.94. In group III of 9 experienced echocardiographers who had not participated in drafting the guidelines, sensitivity was 88±5%, and specificity was 91±7%. Fleiss κ-value for the agreement in group III was 0.76. In group IV of 7 other fellows, sensitivity was 91±3%, and specificity was 92±5%. Fleiss κ-value for the agreement in group IV was 0.89. CONCLUSIONS: There is a good level of agreement and accuracy in the estimation of LV filling pressure using the American Society of Echocardiography/European Association of Cardiovascular Imaging 2016 recommendations update, irrespective of the experience level of the observer.


Sujet(s)
Échocardiographie-doppler/normes , Cardiopathies/imagerie diagnostique , Ventricules cardiaques/imagerie diagnostique , Guides de bonnes pratiques cliniques comme sujet/normes , Fonction ventriculaire gauche , Pression ventriculaire , Sujet âgé , Femelle , Cardiopathies/physiopathologie , Ventricules cardiaques/physiopathologie , Humains , Mâle , Adulte d'âge moyen , Biais de l'observateur , Valeur prédictive des tests , Reproductibilité des résultats
7.
Arch Cardiovasc Dis ; 111(8-9): 487-496, 2018.
Article de Anglais | MEDLINE | ID: mdl-29306705

RÉSUMÉ

BACKGROUND: Diabetes mellitus (DM) has an impact on left ventricular (LV) geometry and function, and is associated with worsening of pressure-overload LV remodelling; however, its impact on volume-overload LV remodelling is unknown. AIM: The objective of the study was to examine the association between DM and LV remodelling in patients with chronic mitral regurgitation (MR) caused by mitral valve prolapse. METHODS: During a median follow-up of 3.26 [interquartile range 1.59-6.06] years, we evaluated the evolution of echocardiographic variables in 375 consecutive patients, including 61 (16%) patients with DM. The main endpoint was LV remodelling evaluated by LV end-diastolic diameter (LVEDD) and LV mass index increase. LV end-systolic diameter (LVESD) and ejection fraction (LVEF) were also evaluated. RESULTS: Patients with DM increased their LVEDD more than patients without DM (1.98±4.1 vs 0.15±4.54mm/year of follow-up; P=0.002). LVEF remained stable in the two groups. After adjustment for potential confounders, including age, sex, hypertension, body mass index, MR severity, medications and follow-up duration, DM remained independently associated with LVEDD increase (ß=2.30; P<0.001). When comparing patients with DM with patients without DM matched for age, sex and LVEDD at baseline, DM was independently associated with increased LVEDD (ß=2.14; P=0.002), LV mass index (ß=10.7; P=0.004) and LVESD (ß=2.07; P=0.01). CONCLUSION: DM is associated with worsening of LV remodelling in patients with moderate or severe chronic MR caused by mitral valve prolapse.


Sujet(s)
Diabète , Insuffisance mitrale/étiologie , Prolapsus de la valve mitrale/complications , Fonction ventriculaire gauche , Remodelage ventriculaire , Sujet âgé , Sujet âgé de 80 ans ou plus , Maladie chronique , Diabète/diagnostic , Diabète/physiopathologie , Échocardiographie-doppler couleur , Femelle , Humains , Mâle , Adulte d'âge moyen , Insuffisance mitrale/imagerie diagnostique , Insuffisance mitrale/physiopathologie , Prolapsus de la valve mitrale/imagerie diagnostique , Prolapsus de la valve mitrale/physiopathologie , Études rétrospectives , Facteurs de risque , Indice de gravité de la maladie , Débit systolique , Facteurs temps
9.
Eur Heart J Cardiovasc Imaging ; 19(1): 67-73, 2018 01 01.
Article de Anglais | MEDLINE | ID: mdl-28165130

RÉSUMÉ

Aims: Diastolic dysfunction is frequent in patients with type 2 diabetes mellitus (DM2) and associated with a poor prognosis. This study aimed to describe diastolic function changes over time in DM2 patients and to identify predictive factors of diastolic function deterioration. Methods and results: Diastolic function was assessed by echocardiography according to the EACVI/ASE recommendations at baseline and 3-year follow-up in a prospective cohort of 310 DM2 patients without overt heart disease. Predictors of diastolic function deterioration were identified using logistic regression analysis. During the 3-year follow-up, prevalence of diastolic dysfunction increased from 49% to 67% (P = 0.001). Only 32% of the patients had a normal diastolic function both at baseline and 3 years and 27% of the patients presented diastolic function deterioration. At multivariable analysis, age (OR = 1.05 [1.01-1.09], P < 0.01), retinopathy (OR = 2.00 [1.10-3.63], P = 0.02), and increase in systolic blood pressure during follow-up (OR = 1.03 [1.01-1.04], P < 0.01) were predictive of diastolic function deterioration. Conclusion: Age, retinopathy, and increase in blood pressure over time are associated with an increased risk of diastolic function deterioration in DM2 patients. The presence of these co-factors might help to early identify patients at risk of heart failure.


Sujet(s)
Diabète de type 2/épidémiologie , Échocardiographie/méthodes , Dysfonction ventriculaire gauche/imagerie diagnostique , Dysfonction ventriculaire gauche/épidémiologie , Adulte , Sujet âgé , Études de cohortes , Comorbidité , Diabète de type 2/diagnostic , Diabète de type 2/traitement médicamenteux , Diastole , Évolution de la maladie , Femelle , Études de suivi , France , Hôpitaux universitaires , Humains , Modèles logistiques , Mâle , Adulte d'âge moyen , Analyse multifactorielle , Valeur prédictive des tests , Études prospectives , Indice de gravité de la maladie , Facteurs temps
10.
Eur Heart J Cardiovasc Imaging ; 18(12): 1301-1310, 2017 Dec 01.
Article de Anglais | MEDLINE | ID: mdl-29045589

RÉSUMÉ

AIMS: This European Association Cardiovascular Imaging (EACVI) Expert Consensus document aims at defining the main quantitative information on cardiac structure and function that needs to be included in standard echocardiographic report following recent ASE/EACVI chamber quantification, diastolic function, and heart valve disease recommendations. The document focuses on general reporting and specific pathological conditions such as heart failure, coronary artery and valvular heart disease, cardiomyopathies, and systemic diseases. METHODS AND RESULTS: Demographic data (age, body surface area, blood pressure, and heart rhythm and rate), type (vendor and model) of ultrasound system used and image quality need to be reported. In addition, measurements should be normalized for body size. Reference normal values, derived by ASE/EACVI recommendations, shall always be reported to differentiate normal from pathological conditions. This Expert Consensus document suggests avoiding the surveillance of specific variable using different ultrasound techniques (e.g. in echo labs with high expertise in left ventricular ejection fraction by 3D and not by 2D echocardiography). The report should be also tailored in relation with different cardiac pathologies, quality of images, and needs of the caregivers. CONCLUSION: The conclusion should be concise reflecting the status of left ventricular structure and function, the presence of left atrial and/or aortic dilation, right ventricular dysfunction, and pulmonary hypertension, leading to an objective communication with the patient health caregiver. Variation over time should be considered carefully, taking always into account the consistency of the parameters used for comparison.


Sujet(s)
Échocardiographie/normes , Valvulopathies/imagerie diagnostique , Guides de bonnes pratiques cliniques comme sujet/normes , Adulte , Techniques d'imagerie cardiaque/normes , Consensus , Diastole/physiologie , Échocardiographie/méthodes , Europe , Femelle , Atrium du coeur/imagerie diagnostique , Ventricules cardiaques/imagerie diagnostique , Humains , Mâle , Normes de référence , Sociétés médicales
11.
J Am Coll Cardiol ; 70(14): 1704-1716, 2017 Oct 03.
Article de Anglais | MEDLINE | ID: mdl-28958326

RÉSUMÉ

BACKGROUND: Type 2 diabetes mellitus (T2DM) may alter cardiac structure and function, but obesity, hypertension (HTN), or aging can induce similar abnormalities. OBJECTIVES: This study sought to link cardiac phenotypes in T2DM patients with clinical profiles and outcomes using cluster analysis. METHODS: Baseline echocardiography and a composite endpoint (cardiovascular mortality and hospitalization) were evaluated in 842 T2DM patients from 2 prospective cohorts. A cluster analysis was performed on echocardiographic variables, and the association between clusters and clinical profiles and outcomes was assessed. RESULTS: Three clusters were identified. Cluster 1 patients had the lowest left ventricular (LV) mass index and ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') ratio, had the highest left ventricular ejection fraction (LVEF), and were predominantly male with the lowest rate of obesity or HTN. Cluster 2 patients had the highest strain and highest E/e' ratio, were the oldest, were predominantly female, and had the lowest rate of isolated T2DM (without HTN or obesity). Cluster 3 patients had the highest LV mass index and volumes and the lowest LVEF and strain, were predominantly male, and shared similar age and rate of obesity and HTN as cluster 1 patients. After follow-up of 67 months (interquartile range: 40 to 87), the composite endpoint occurred in 56 of 521 patients (10.8%). Clusters 2 (hazard ratio: 2.37; 95% confidence interval: 1.15 to 4.88) and 3 (hazard ratio: 2.19; 95% confidence interval: 1.00 to 4.82) had a similar outcome, which was worse than cluster 1. CONCLUSIONS: Cluster analysis of echocardiographic variables identified 3 different echocardiographic phenotypes of T2DM patients that were associated with distinct clinical profiles and highlighted the prognostic value of LV remodeling and subclinical dysfunction.


Sujet(s)
Maladies cardiovasculaires/mortalité , Diabète de type 2 , Échocardiographie/méthodes , Dysfonction ventriculaire gauche , Remodelage ventriculaire , Sujet âgé , Maladies asymptomatiques , Analyse de regroupements , Diabète de type 2/épidémiologie , Diabète de type 2/physiopathologie , Femelle , France/épidémiologie , Humains , Mâle , Adulte d'âge moyen , Pronostic , Appréciation des risques , Facteurs de risque , Statistiques comme sujet , Débit systolique , Dysfonction ventriculaire gauche/diagnostic , Dysfonction ventriculaire gauche/physiopathologie , Fonction ventriculaire gauche
12.
Eur Heart J Cardiovasc Imaging ; 18(10): 1090-1121, 2017 Oct 01.
Article de Anglais | MEDLINE | ID: mdl-28510718

RÉSUMÉ

Restrictive cardiomyopathies (RCMs) are a diverse group of myocardial diseases with a wide range of aetiologies, including familial, genetic and acquired diseases and ranging from very rare to relatively frequent cardiac disorders. In all these diseases, imaging techniques play a central role. Advanced imaging techniques provide important novel data on the diagnostic and prognostic assessment of RCMs. This EACVI consensus document provides comprehensive information for the appropriateness of all non-invasive imaging techniques for the diagnosis, prognostic evaluation, and management of patients with RCM.


Sujet(s)
Techniques d'imagerie cardiaque/normes , Cardiomyopathie restrictive/imagerie diagnostique , Imagerie multimodale/normes , Guides de bonnes pratiques cliniques comme sujet , Cardiologie/normes , Cardiomyopathies/imagerie diagnostique , Consensus , Europe , Femelle , Humains , IRM dynamique/normes , Mâle , Péricardite/imagerie diagnostique , Sociétés médicales
13.
Eur Heart J Cardiovasc Imaging ; 18(11): 1283-1291, 2017 Nov 01.
Article de Anglais | MEDLINE | ID: mdl-28062567

RÉSUMÉ

AIM: Long-term high-fat diet (HFD) induces both cardiac remodelling and myocardial dysfunction in murine models. The aim was to assess the time course and mechanisms of metabolic and cardiac modifications induced by short-term HFD in wild-type (WT) mice. METHODS AND RESULTS: Thirty-three WT mice were subjected to HFD (60% fat, n = 16) and chow diet (CD, 13% fat, n = 17). Metabolic and echocardiographic data were collected at baseline and every 5 weeks for 20 weeks. Invasive haemodynamic data and myocardial samples were collected at 5 and 20 weeks. Echocardiographic data included left ventricular (LV) diameters and thickness, and systolic function using radial strain rate (SR). Histological assessment of cardiomyocyte and adipocyte sizes, interstitial fibrosis, and apoptosis index were performed. During follow-up, body weight, and glycaemia levels were higher in HFD than in CD mice, in association with an early adipose tissue remodelling. Despite no difference between both groups in blood pressure and LV mass at 5 weeks, an early LV dysfunction was observed in HFD mice as assessed by radial SR (21 ± 0.8 vs. 27 ± 0.8 unit/s, P < 0.001) and haemodynamic assessment. During follow-up, both groups demonstrated a progressive systolic and diastolic LV dysfunction and remodelling including dilatation and hypertrophy, which were more severe in HFD mice. Compared with CD mice, the early LV impairment in HFD mice was coupled with a higher cardiomyocyte apoptosis level (0.95 vs. 0.02%, P < 0.05) associated with an interstitial fibrosis process (2.3 vs. 0.2%, P < 0.05), which worsen during follow-up. CONCLUSION: The HFD promoted early metabolic and cardiac dysfunctions, and adipose and myocardial tissues remodelling.


Sujet(s)
Cardiomyopathies/imagerie diagnostique , Cardiomyopathies/étiologie , Alimentation riche en graisse , Échocardiographie , Animaux , Apoptose , Marqueurs biologiques/métabolisme , Hyperglycémie provoquée , Humains , Méthode TUNEL , Insuline/métabolisme , Mâle , Malonaldéhyde/métabolisme , Souris , Souris de lignée C57BL , Remodelage ventriculaire
14.
NMR Biomed ; 29(7): 978-84, 2016 07.
Article de Anglais | MEDLINE | ID: mdl-27226402

RÉSUMÉ

Recent studies have suggested that brown adipose tissue (BAT) plays an important role in obesity, insulin resistance and heart failure. The characterization of BAT in vivo, however, has been challenging. No technique to comprehensively image BAT anatomy and function has been described. Moreover, the impact on BAT of the neuroendocrine activation seen in heart failure has only recently begun to be evaluated in vivo. The aim of this study was to use MRI to characterize the impact of heart failure on the morphology and function of BAT. Mice subjected to permanent ligation of the left coronary artery were imaged with MRI 6 weeks later. T2 weighted MRI of BAT volume and blood oxygen level dependent MRI of BAT function were performed. T2 * maps of BAT were obtained at multiple time points before and after administration of the ß3 adrenergic agonist CL 316 243 (CL). Blood flow to BAT was studied after CL injection using the flow alternating inversion recovery (FAIR) approach. Excised BAT tissue was analyzed for lipid droplet content and for uncoupling protein 1 (UCP1) mRNA expression. BAT volume was significantly lower in heart failure (51 ± 1 mm(3) versus 65 ± 3 mm(3) ; p < 0.05), and characterized by a reduction in lipid globules and a fourfold increase in UCP1 mRNA (p < 0.05). CL injection increased BAT T2 * in healthy animals but not in mice with heart failure (24 ± 4% versus 6 ± 2%; p < 0.01), consistent with an increase in flow in control BAT. This was confirmed by a significant difference in the FAIR response in BAT in control and heart failure mice. Heart failure results in the chronic activation of BAT, decreased BAT lipid stores and decreased BAT volume, and it is associated with a marked decrease in ability to respond to acute physiological stimuli. This may have important implications for substrate utilization and overall metabolic homeostasis in heart failure. Copyright © 2016 John Wiley & Sons, Ltd.


Sujet(s)
Tissu adipeux brun/métabolisme , Tissu adipeux brun/anatomopathologie , Techniques d'imagerie cardiaque/méthodes , Défaillance cardiaque/imagerie diagnostique , Défaillance cardiaque/métabolisme , Imagerie par résonance magnétique/méthodes , Oxygène/sang , Tissu adipeux brun/imagerie diagnostique , Animaux , Femelle , Défaillance cardiaque/anatomopathologie , Gouttelettes lipidiques/métabolisme , Mâle , Souris , Souris de lignée C57BL , Oxymétrie/méthodes
15.
Int J Stroke ; 11(6): 724-32, 2016 08.
Article de Anglais | MEDLINE | ID: mdl-27056964

RÉSUMÉ

RATIONALE: Currently available data do not provide definitive evidence on the comparative benefits of closure of patent foramen ovale, oral anticoagulants and antiplatelet therapy in patients with patent foramen ovale-associated cryptogenic stroke AIM: To assess whether transcatheter patent foramen ovale closure plus antiplatelet therapy is superior to antiplatelet therapy alone and whether oral anticoagulant therapy is superior to antiplatelet therapy, for secondary stroke prevention in patients aged 16 to 60 years with a large patent foramen ovale or a patent foramen ovale associated with an atrial septal aneurysm, and an otherwise unexplained ischaemic stroke or retinal ischaemia. SAMPLE SIZE: Six hundred and sixty-four patients were included in the study. METHODS AND DESIGN: CLOSE is an academic-driven, multicentre, randomized, open-label, three-group, superiority trial with blinded adjudication of outcome events. The trial has been registered with Clinical Trials Register (Clinicaltrials.gov, NCT00562289). Patient recruitment started in December 2007. Patient follow-up will continue until December 2016. Expected mean follow-up = 5.6 years. STUDY OUTCOMES: The primary efficacy outcome is the occurrence of fatal or nonfatal stroke. Safety outcomes include fatal, life-threatening or major procedure- or device-related complications and fatal, life-threatening or major haemorrhagic complications. DISCUSSION: CLOSE is the first specifically designed trial to assess the superiority of patent foramen ovale closure over antiplatelet therapy alone and the superiority of oral anticoagulants over antiplatelet therapy to prevent stroke recurrence in patients with patent foramen ovale-associated cryptogenic stroke.


Sujet(s)
Anticoagulants/usage thérapeutique , Foramen ovale perméable/traitement médicamenteux , Foramen ovale perméable/chirurgie , Antiagrégants plaquettaires/usage thérapeutique , Administration par voie orale , Adolescent , Adulte , Anticoagulants/effets indésirables , Anticoagulants/économie , Procédures de chirurgie cardiaque/effets indésirables , Procédures de chirurgie cardiaque/économie , Femelle , Études de suivi , Humains , Mâle , Adulte d'âge moyen , Sélection de patients , Antiagrégants plaquettaires/effets indésirables , Antiagrégants plaquettaires/économie , Complications postopératoires/économie , Prévention secondaire/économie , Accident vasculaire cérébral/prévention et contrôle , Résultat thérapeutique , Jeune adulte
16.
Am J Physiol Heart Circ Physiol ; 310(8): H984-94, 2016 Apr 15.
Article de Anglais | MEDLINE | ID: mdl-26873969

RÉSUMÉ

Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.


Sujet(s)
Récepteur activine, type 1/métabolisme , Angiotensine-II , Protéine morphogénétique osseuse de type 2/pharmacologie , Protéine morphogénétique osseuse de type 4/pharmacologie , Récepteurs de la protéine morphogénique osseuse de type I/métabolisme , Cardiomégalie/enzymologie , Myocytes cardiaques/enzymologie , Récepteur activine, type 1/déficit , Récepteur activine, type 1/génétique , Récepteur activine, type 2 , Animaux , Récepteurs de la protéine morphogénique osseuse de type I/déficit , Récepteurs de la protéine morphogénique osseuse de type I/génétique , Cardiomégalie/induit chimiquement , Cardiomégalie/génétique , Cardiomégalie/anatomopathologie , Cardiomégalie/prévention et contrôle , Cellules cultivées , Modèles animaux de maladie humaine , Relation dose-effet des médicaments , Fibrose , Protéine d'inhibition de la différenciation de type 1/génétique , Protéine d'inhibition de la différenciation de type 1/métabolisme , Souris de lignée C57BL , Souris knockout , Myocytes cardiaques/effets des médicaments et des substances chimiques , Myocytes cardiaques/anatomopathologie , Facteurs de transcription NFATC/métabolisme , Phényléphrine/pharmacologie , Phosphorylation , Pyrazoles/pharmacologie , Pyrimidines/pharmacologie , Interférence par ARN , Rat Sprague-Dawley , Transduction du signal , Protéines Smad/génétique , Protéines Smad/métabolisme , Facteurs temps , Transfection
17.
J Appl Physiol (1985) ; 120(8): 825-32, 2016 Apr 15.
Article de Anglais | MEDLINE | ID: mdl-26823340

RÉSUMÉ

Brown adipose tissue (BAT) activation increases glucose and lipid consumption; as such, it is been considered as a potential therapy to decrease obesity. BAT is highly vascularized and its activation is associated with a necessary increase in blood flow. However, whether increasing BAT blood flow per se increases BAT activity is unknown. To examine this hypothesis, we investigated whether an isolated increase in BAT blood flow obtained by ß2-adrenoreceptor (ß2-AR) stimulation with salbutamol increased BAT activity. BAT blood flow was estimated in vivo in mice using contrast-enhanced ultrasound. The absence of direct effect of salbutamol on the function of isolated brown adipocytes was assessed by measuring oxygen consumption. The effect of salbutamol on BAT activity was investigated by measuring BAT glucose uptake in vivo. BAT blood flow increased by 2.3 ± 0.6-fold during ß2-AR stimulation using salbutamol infusion in mice (P= 0.003). ß2-AR gene expression was detectable in BAT but was extremely low in isolated brown adipocytes. Oxygen consumption of isolated brown adipocytes did not change with salbutamol exposure, confirming the absence of a direct effect of ß2-AR agonist on brown adipocytes. Finally, ß2-AR stimulation by salbutamol increased BAT glucose uptake in vivo (991 ± 358 vs. 135 ± 49 ng glucose/mg tissue/45 min in salbutamol vs. saline injected mice, respectively,P= 0.046). In conclusion, an increase in BAT blood flow without direct stimulation of the brown adipocytes is associated with increased BAT metabolic activity. Increasing BAT blood flow might represent a new therapeutic target in obesity.


Sujet(s)
Tissu adipeux brun/métabolisme , Tissu adipeux brun/physiologie , Récepteurs bêta-2 adrénergiques/métabolisme , Animaux , Transport biologique/physiologie , Glucose/métabolisme , Mâle , Souris , Souris de lignée C57BL , Obésité/métabolisme , Obésité/physiopathologie , Consommation d'oxygène/physiologie , Débit sanguin régional/physiologie
18.
Eur Heart J Cardiovasc Imaging ; 17(2): 117-9, 2016 Feb.
Article de Anglais | MEDLINE | ID: mdl-26690950

RÉSUMÉ

The purpose of this review is to summarize the activity and potential of the young community of European Association of Cardiovascular Imaging and to highlight the transition from Club 35 to 'Heart Imagers of tomorrow'.


Sujet(s)
Maladies cardiovasculaires/diagnostic , Imagerie diagnostique , Sociétés médicales/organisation et administration , Europe , Humains
19.
J Mol Cell Cardiol ; 84: 202-11, 2015 Jul.
Article de Anglais | MEDLINE | ID: mdl-25968336

RÉSUMÉ

Brown adipose tissue (BAT) has well recognized thermogenic properties mediated by uncoupling protein 1 (UCP1); more recently, BAT has been demonstrated to modulate cardiovascular risk factors. To investigate whether BAT also affects myocardial injury and remodeling, UCP1-deficient (UCP1(-/-)) mice, which have dysfunctional BAT, were subjected to catecholamine-induced cardiomyopathy. At baseline, there were no differences in echocardiographic parameters, plasma cardiac troponin I (cTnI) or myocardial fibrosis between wild-type (WT) and UCP1(-/-) mice. Isoproterenol infusion increased cTnI and myocardial fibrosis and induced left ventricular (LV) hypertrophy in both WT and UCP1(-/-) mice. UCP1(-/-) mice also demonstrated exaggerated myocardial injury, fibrosis, and adverse remodeling, as well as decreased survival. Transplantation of WT BAT to UCP1(-/-) mice prevented the isoproterenol-induced cTnI increase and improved survival, whereas UCP1(-/-) BAT transplanted to either UCP1(-/-) or WT mice had no effect on cTnI release. After 3 days of isoproterenol treatment, phosphorylated AKT and ERK were lower in the LV's of UCP1(-/-) mice than in those of WT mice. Activation of BAT was also noted in a model of chronic ischemic cardiomyopathy, and was correlated to LV dysfunction. Deficiency in UCP1, and accompanying BAT dysfunction, increases cardiomyocyte injury and adverse LV remodeling, and decreases survival in a mouse model of catecholamine-induced cardiomyopathy. Myocardial injury and decreased survival are rescued by transplantation of functional BAT to UCP1(-/-) mice, suggesting a systemic cardioprotective role of functional BAT. BAT is also activated in chronic ischemic cardiomyopathy.


Sujet(s)
Tissu adipeux brun/physiologie , Cardiomyopathies/anatomopathologie , Cardiomyopathies/physiopathologie , Catécholamines/effets indésirables , Remodelage ventriculaire , Tissu adipeux brun/transplantation , Animaux , Marqueurs biologiques/métabolisme , Pression sanguine/effets des médicaments et des substances chimiques , Poids/effets des médicaments et des substances chimiques , Cardiomyopathies/induit chimiquement , Cardiomyopathies/imagerie diagnostique , Cardiotoniques/métabolisme , Catécholamines/administration et posologie , Extracellular Signal-Regulated MAP Kinases/métabolisme , Fibrose , Régulation de l'expression des gènes/effets des médicaments et des substances chimiques , Défaillance cardiaque/complications , Défaillance cardiaque/enzymologie , Défaillance cardiaque/anatomopathologie , Défaillance cardiaque/physiopathologie , Ventricules cardiaques/effets des médicaments et des substances chimiques , Ventricules cardiaques/métabolisme , Canaux ioniques/déficit , Canaux ioniques/génétique , Canaux ioniques/métabolisme , Isoprénaline/pharmacologie , Mâle , Souris de lignée C57BL , Protéines mitochondriales/déficit , Protéines mitochondriales/génétique , Protéines mitochondriales/métabolisme , Myocarde/anatomopathologie , Myocytes cardiaques , Phosphorylation/effets des médicaments et des substances chimiques , Protéines proto-oncogènes c-akt/métabolisme , Transduction du signal/effets des médicaments et des substances chimiques , Analyse de survie , Échographie , Protéine-1 de découplage , Remodelage ventriculaire/effets des médicaments et des substances chimiques
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