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1.
Am J Physiol Heart Circ Physiol ; 321(3): H509-H517, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34242095

RESUMO

Left ventricular (LV) remodeling, characterized by increased LV hypertrophy and depressed systolic and diastolic function, is observed in strength-trained athletes who use anabolic-androgenic steroids (AAS). Previous studies suggested a pathological remodeling with an increase in cardiac fibrosis in these athletes, which could promote intraventricular dyssynchrony. In this context, this study evaluated LV dyssynchrony in strength-trained athletes using AAS, hypothesizing that the use of AAS would lead to an increase in post-systolic shortening. Forty-four male subjects (aged 20-40 yr) were divided into three age-matched groups: strength-trained athletes using (users, n = 14) or not (nonusers, n = 15) AAS and healthy sedentary men (controls, n = 15). After completing a survey, each participant was assessed with two-dimensional (2D)-strain echocardiography. LV dyssynchrony was quantified using the standard deviation (SD) of the time to peak for longitudinal strain of the 18 LV-segments (from the apical 4, 3, and 2 chambers views), the longitudinal strain delay index (LSDI), and the segmental post-systolic index (PSI). Users showed mean AAS dosages of 564 ± 288 mg[Formula: see text]wk-1 with a mean protocol duration of 12 ± 6 wk and a history of use of 4.7 ± 1.8 yr. They exhibited a greater LV mass index and depressed systolic and diastolic function when compared with both nonusers and controls. The decrease in LV strain in users was predominantly observed at the interventricular septum level (-16.9% ± 2.5% vs. -19.2% ± 1.8% and -19.0% ± 1.6% in users, nonusers, and controls, respectively, P < 0.01). Users showed higher SD than controls (43 ± 8 ms vs. 32 ± 5 ms, respectively, P < 0.01). The LSDI was significantly higher in users compared with both nonusers and controls (-23.4 ± 9.5 vs. -15.9 ± 9.3 and -9.8 ± 3.9, respectively, P < 0.01). PSI, calculated on the basal inferoseptal, basal anteroseptal, and basal inferolateral segments, were also greater in users compared with the two other groups. Our results reported an increase in LV dyssynchrony in young AAS users that brought new evidences of a pathologic cardiac remodeling in this specific population.NEW & NOTEWORTHY Illicit androgenic anabolic steroids (AAS) use is widespread, but data on LV dyssynchrony are lacking, although it could be increased by a higher prevalence of myocardial fibrosis reported in this population. In AAS users, the decrease in LV strain was predominantly observed in interventricular segments. All dyssynchrony indices were higher in AAS users and several segments exhibited post-systolic shortening. These results showed an association between AAS consumption, LV remodeling, and dyssynchrony.


Assuntos
Exercício Físico , Ventrículos do Coração/efeitos dos fármacos , Contração Miocárdica , Congêneres da Testosterona/farmacologia , Função Ventricular Esquerda , Adolescente , Adulto , Atletas , Humanos , Masculino , Congêneres da Testosterona/efeitos adversos , Remodelação Ventricular
2.
Graefes Arch Clin Exp Ophthalmol ; 257(1): 125-134, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30413876

RESUMO

PURPOSE: To investigate preoperative ocular risk factors and indications for secondary intraocular lens (IOL) implantation and compare postoperative complications, visual and refractive outcomes in a tertiary referral center. METHODS: Patients older than 14 years that underwent secondary IOL implantation and had a minimum follow-up of 3 months were enrolled in this retrospective case series. Preoperative ocular risk factors, indications for surgery, postoperative complications, and visual and refractive outcomes including prediction error (PE) and absolute error (AE) were evaluated. IOLs were fixated in following positions: anterior chamber (AC), retropupillary iris-claw (IC), sulcus, and capsular bag or sclera. RESULTS: One-hundred eighty-two eyes of 174 patients with mean follow-up of 17 ± 13.6 months were evaluated. Leading cause for surgery was IOL dislocation (75%), followed by secondary aphakia (19%) and IOL opacifications (6%). Previous vitrectomy was the major preoperative ocular risk factor (43%). Mean corrected distance visual acuity improved from preoperative 0.68 ± 0.55 to 0.42 ± 0.31LogMAR by the last follow-up (p = 0.001). PE and AE differed highly depending on the indication for surgery (p = 0.041 and p = 0.008, respectively) and the IOL fixation (p = 0.011 and p = 0.028, respectively), with IC-IOLs showing the lowest PE and AE. Postoperative AC-hemorrhage occurred mainly after IC-IOLs (p = 0.003), and postoperative hypotony was significantly higher in eyes with previous uveitis (p = 0.026). CONCLUSIONS: Previous vitrectomy seems to be a major underreported risk factor in eyes that undergo secondary IOL implantation. Refractive outcomes depend on indication for surgery and fixation type, with retropupillary IC-IOLs providing the best refractive results, though not statistically significant compared to other IOL positions.


Assuntos
Afacia Pós-Catarata/cirurgia , Implante de Lente Intraocular/métodos , Complicações Pós-Operatórias/epidemiologia , Refração Ocular/fisiologia , Acuidade Visual , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Afacia Pós-Catarata/fisiopatologia , Feminino , Seguimentos , Alemanha/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
3.
Am J Physiol Heart Circ Physiol ; 310(10): H1340-8, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26921434

RESUMO

Investigations on the cardiac function consequences of mountain ultramarathon (MUM) >100 h are lacking. The present study assessed the progressive cardiac responses during the world's most challenging MUM (Tor des Géants; Italy; 330 km; 24,000 m of cumulative elevation gain). Resting echocardiographic evaluation of morphology, function, and mechanics of left and right ventricle (LV and RV) including speckle tracking echocardiography was conducted in 15 male participants (46 ± 13 yr) before (pre), during (mid; 148 km), and after (post) the race. Runners completed the race in 126 ± 15 h. From pre to post, the increase in stroke volume (SV) (103 ± 19 vs. 110 ± 23 vs. 116 ± 21 ml; P < 0.001 at pre, mid, and post) was concomitant to the increase in LV early filling (peak E; 72.9 ± 15.7 vs. 74.6 ± 13.1 vs. 82.1 ± 11.5 cm/s; P < 0.05). Left and right atrial end-diastolic areas, RV end-diastolic area, and LV end-diastolic volume were 12-19% higher at post compared with pre (P < 0.05). Resting heart rate and LV systolic strain rates demonstrated a biphasic adaptation with an increase from pre to mid (55 ± 8 vs. 72 ± 11 beats/min, P < 0.001) and a return to baseline values from mid to post (59 ± 8 beats/min). Significant correlations were found between pre-to-post percent changes in peak E and LV end-diastolic volume (r = 0.63, P < 0.05) or RV (r = 0.82, P < 0.001) or atrial end-diastolic areas (r = 0.83, P < 0.001). An extreme MUM induced a biphasic pattern of heart rate in parallel with specific cardiac responses characterized by a progressive increase in diastolic filling, biventricular volumes, and SV. The underlying mechanisms and their clinical implications remain challenging for the future.


Assuntos
Aclimatação , Altitude , Cardiomegalia Induzida por Exercícios , Frequência Cardíaca , Resistência Física/fisiologia , Corrida , Função Ventricular Esquerda , Função Ventricular Direita , Adulto , Diástole , Ecocardiografia Doppler , Humanos , Masculino , Pessoa de Meia-Idade , Sístole , Fatores de Tempo , Adulto Jovem
4.
Clin Sci (Lond) ; 130(5): 365-76, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26608078

RESUMO

ERß (oestrogen receptor ß) activation has been shown to be cardioprotective, but the cell types and mechanisms involved are not understood. To investigate whether ERß restricted to cardiomyocytes contributes to the observed cardioprotection, we tested the effects of cardiomyocyte-specific ERß-OE (ERß overexpression) on survival, cardiac remodelling and function after MI (myocardial infarction) and studied the molecular pathways potentially involved. Female and male mice with cardiomyocyte-specific ERß-OE and WT (wild-type) littermates were subjected to chronic anterior coronary artery ligation or sham surgery. Two weeks after MI, ERß-OE mice showed improved survival (100% and 83% compared with 76% and 58% in WT females and males respectively). ERß-OE was associated with attenuated LV (left ventricular) dilatation, smaller increase in heart weight, less lung congestion at similar MI size, and improved systolic and diastolic function in both sexes. We identified two potential pathways for ERß-mediated myocardial protection. First, male and female ERß-OE mice had a lower reduction of SERCA2a (sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase 2a) expression after MI, suggesting less reduction in diastolic Ca(2+)-reuptake into the sarcoplasmic reticulum post-MI. Secondly, male ERß-OE revealed attenuated cardiac fibrosis in the remote LV tissue and expression of fibrosis markers collagen I and III, periostin and miR-21. Cardiomyocyte-specific ERß-OE improved survival associated with reduced maladaptive remodelling, improved cardiac function and less heart failure development after MI in both sexes. These effects seem to be related, at least in part, to a better maintenance of Ca(2+) cycling in both sexes and a lower induction of cardiac fibrosis in males after MI.


Assuntos
Receptor beta de Estrogênio/metabolismo , Infarto do Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Biomarcadores/metabolismo , Diástole/fisiologia , Receptor beta de Estrogênio/fisiologia , Feminino , Fibrose , Masculino , Camundongos Transgênicos , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Fatores Sexuais , Sístole/fisiologia , Ultrassonografia , Remodelação Ventricular/fisiologia
5.
Med Sci Sports Exerc ; 54(5): 780-788, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34974501

RESUMO

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 (LV) strains but did not assess LV twist and untwist mechanics. Moreover, left atrial (LA) function has been often neglected, and its stiffness, an important determinant of LA reservoir function, has never been challenged. The aim of this study was to investigate the effects of AAS on LA and LV morphologies and functions in strength athletes. METHODS: Fifty subjects including 20 strength-trained young athletes age 32.0 ± 8.5 yr with a mean duration of AAS use of 4.7 ± 1.8 yr (users), 15 athletes with no history of AAS use (nonusers) and 15 sedentary controls underwent speckle tracking echocardiography to assess LA and LV morphology and function. RESULTS: Users showed higher LA reservoir dysfunction than nonusers (33.7% ± 10.9% vs 44.9% ± 9.9% respectively, P = 0.004) and higher LA stiffness (0.13 ± 0.05 vs 0.19 ± 0.08 A.U., respectively; P = 0.02), higher LV mass index and lower global and regional LV diastolic and systolic dysfunction (global longitudinal strain: -15.5% ± 3.2% vs -18.9% ± 1.8% respectively; P = 0.003), with a drop of LV twist-untwist mechanics (untwisting velocity: 61.5°·s-1 ± 20.2°·s-1 vs 73.7°·s-1 ± 16.1°·s-1 respectively, P = 0.04). There were significant correlations between LV mass and LV apical rotation (P = 0.003, r = 0.44) and diastolic longitudinal strain rate (P = 0.015, r = 0.33). CONCLUSIONS: Our results showing significant LA and LV remodeling and dysfunctions in young AAS using athletes are alarming. Screening echocardiography based on speckle tracking echocardiography parameters for early diagnosis, as well as a stronger awareness in athletes and in physicians are warranted in this context.


Assuntos
Ecocardiografia , Ventrículos do Coração , Adulto , Atletas , Ecocardiografia/métodos , Ventrículos do Coração/diagnóstico por imagem , Humanos , Congêneres da Testosterona/efeitos adversos , Função Ventricular Esquerda , Remodelação Ventricular , Adulto Jovem
6.
Arch Cardiovasc Dis ; 115(11): 562-570, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36207245

RESUMO

BACKGROUND: SARS-CoV-2 infection can induce cardiac damage. Therefore, in the absence of clear data, a cardiac evaluation was recommended for athletes before returning to play after recent SARS-CoV-2 infection. AIM: To assess the proportion of anomalies detected by this cardiac screening. METHODS: We reviewed the medical files of elite athletes referred for cardiac evaluation before returning to play after a non-hospitalized SARS-CoV-2 infection (based on a positive polymerase chain reaction or antigen test) from March 2020 to July 2021 in 12 French centres. RESULTS: A total of 554 elite athletes (professional or national level) were included (median age 22 years, 72.0% male). An electrocardiogram (ECG), echocardiogram and exercise test were performed in 551 (99.5%), 497 (89.7%) and 293 (52.9%) athletes, respectively. We found anomalies with a potential link with SARS-CoV-2 infection in four ECGs (0.7%), three echocardiograms (0.6%) and three exercise tests (1.0%). Cardiac magnetic resonance imaging was performed in 34 athletes (6.1%), mostly due to abnormal first-line examinations, and was abnormal in one (2.9%). The rates of those abnormalities were not higher among athletes with cardiac symptoms or more severe forms of non-hospitalized SARS-CoV-2 infection. Only one athlete had a possible SARS-CoV-2 myocarditis and sport was temporally contraindicated. None had a major cardiac event declared during the follow-up. CONCLUSION: The proportion of cardiac involvement after non-hospitalized forms of SARS-CoV-2 infection in athletes are very low. Systematic cardiac screening before returning to play seems to be unnecessary.


Assuntos
COVID-19 , Miocardite , Masculino , Humanos , Adulto Jovem , Adulto , Feminino , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2 , Atletas , Coração
7.
Turk J Emerg Med ; 20(3): 97-104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32832728

RESUMO

OBJECTIVES: Global longitudinal strain (GLS) appears sensitive and reproducible to identify left ventricular systolic dysfunction. The main objective was to analyze the GLS changes in an anesthetized-piglet model of controlled hemorrhagic shock (HS). The secondary objective was to evaluate if GLS changes was different depending on the expansion fluid treatment with or without norepinephrine. METHODS: Eighteen anesthetized and ventilated piglets were bled until the mean arterial pressure reached 40 mmHg. Controlled hemorrhage was maintained for 30 min before randomizing the piglets to three resuscitation groups: control group, LR group (resuscitated with lactated ringer), and NA group (resuscitated with lactated ringer and norepinephrine). RESULTS: There was no difference in the baseline hemodynamic, biological, and ultrasound data among the three groups. During the hemorrhagic phase, the GLS increased significantly from 25 mL/kg of depletion. During the resuscitation phase, the GLS decreased significantly from 20 mL/kg of fluid administration. There was no difference in GLS variation among the groups during the hemorrhagic, maintenance, and resuscitation phases. CONCLUSION: In our HS model, GLS increased with hemorrhage and decreased during resuscitation, showing its preload dependence.

8.
Am J Kidney Dis ; 53(2): 281-9, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19100670

RESUMO

BACKGROUND: Basal nitric oxide (NO) activity has a pivotal role in the regulation of glomerular hemodynamics, and in animal experiments, its alteration has been associated with morphological changes characteristic of diabetic nephropathy. STUDY DESIGN: Prospective observational-study during a mean follow-up of 2.1 years. SETTING & PARTICIPANTS: 66 hypertensive patients (aged 30 to 80 years) with type 2 diabetes and estimated glomerular filtration rate (GFR) greater than 80 mL/min/1.73 m(2) with normoalbuminuria or microalbuminuria. PREDICTOR: Mean arterial pressure during follow-up during treatment with telmisartan or ramipril for 9 weeks, followed by treatment according to the discretion of the individual primary care physician. OUTCOMES & MEASUREMENTS: Renal vascular resistance, renal plasma flow, GFR, and change in renal plasma flow in response to infusion of the NO synthase inhibitor N-monomethyl-L-arginine as an indicator of basal NO activity in the renal vasculature. RESULTS: 50 of 66 patients could be reexamined. At follow-up, mean arterial pressure decreased from 106 +/- 9.1 to 100 +/- 11 mm Hg (P < 0.001). Body mass index and hemoglobin A(1c) levels were unaltered. Renal vascular resistance decreased (from 128 +/- 44 to 103 +/- 30 mm Hg/mL/min/1.73 m(2); P < 0.001), renal plasma flow increased (from 490 +/- 133 to 589 +/- 154 mL/min/1.73 m(2); P < 0.001), and GFR did not change (113 +/- 22 versus 116 +/- 26 mL/min/1.73 m(2); P = 0.4) during follow-up. The decrease in renal plasma flow in response to N-monomethyl-l-arginine infusion was more pronounced at follow-up (-56.7 +/- 39 versus -73.4 +/- 48 mL/min/1.73 m(2); P = 0.02), indicating improved basal NO activity. After adjustment for possible confounders, patients with a marked decrease in mean arterial pressure showed more improved basal NO activity during follow-up than those with a less pronounced decrease in mean arterial pressure (P = 0.04). LIMITATIONS: Patients were treated according to the discretion of the individual primary care physician. CONCLUSIONS: During follow-up, renal vascular resistance, renal plasma flow, and renal endothelial function (indicated by basal NO activity) improved. Better blood pressure control was associated with improved endothelial function of the renal vasculature, thereby potentially mediating the changes in renal hemodynamics.


Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Endotélio Vascular/fisiopatologia , Hipertensão/complicações , Rim/irrigação sanguínea , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Benzimidazóis/uso terapêutico , Benzoatos/uso terapêutico , Pressão Sanguínea , Diabetes Mellitus Tipo 2/complicações , Endotélio Vascular/efeitos dos fármacos , Feminino , Taxa de Filtração Glomerular , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Ramipril/uso terapêutico , Fluxo Plasmático Renal/efeitos dos fármacos , Telmisartan , Resistência Vascular/efeitos dos fármacos , Ácido p-Aminoipúrico
9.
Med Sci Sports Exerc ; 51(9): 1838-1844, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30973478

RESUMO

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 HR 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 diastolic and systolic function parameters, including twist-untwist mechanics, to SV adaptation during the first minutes after exercise onset. METHODS: Diastolic and systolic myocardial strains and twist were monitored by two-dimensional speckle-tracking echocardiography with high temporal resolution in 28 young men (mean age, 23 ± 4 yr) who performed five similar constant work-load exercises on a cycloergometer (target HR: 125 bpm). Two-dimensional cine-loops were recorded every 15 s during the first minute of exercise, and then every 30 s for the next 3 min. RESULTS: During the first 60 s of exercise, SV (from 104 ± 15 mL to 126 ± 21 mL, P < 0.001) increased concomitantly with LV strain and strain rates. Early filling was the main SV determinant during this phase, probably linked to the increase of venous return (at the very beginning of exercise), LV relaxation (from 1.5 ± 0.3 s to 2.5 ± 0.4 s, P < 0.001) and untwisting (from -78 ± 34°·s to -165 ± 61°·s, P < 0.001). After the first minute, SV remained constant, whereas LV untwisting continued to increase (from -165 ± 61°·s to -187 ± 60°·s, P < 0.001) and the other systolic and diastolic parameters reached a plateau. CONCLUSIONS: This study gives new mechanical insights into LV kinetics to address the challenge of SV response at the onset of exercise.


Assuntos
Exercício Físico/fisiologia , Descanso/fisiologia , Função Ventricular Esquerda/fisiologia , Adaptação Fisiológica , Adolescente , Adulto , Diástole/fisiologia , Ecocardiografia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Volume Sistólico/fisiologia , Sístole/fisiologia , Adulto Jovem
10.
Am J Cardiol ; 101(8): 1213-7, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18394461

RESUMO

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 receiving HAART for > or =2 years with no clinical evidence of cardiovascular disease. Echocardiography at rest, including tissue Doppler imaging and exercise testing, were performed in 30 HIV(+) men (age 42.1 +/- 4.7 years, duration of HIV infection 10.4 +/- 4.7 years, duration of HAART 5.3 +/- 2.1 years) and 26 age-matched healthy controls. At rest, HIV(+) patients had similar left ventricular (LV) mass indexed to height(2.7) (40.6 +/- 9.5 vs 37.5 +/- 9.3 g/m; p >0.05), but a higher prevalence of LV diastolic dysfunction (abnormal relaxation or pseudonormal filling pattern in 64% of patients vs 12% of controls; p <0.001). LV systolic function indexes were significantly lower (ejection fraction 60.4 +/- 8.7% vs 66.9 +/- 6.9%; p <0.01, and tissue Doppler imaging peak systolic velocity 11.4 +/- 1.6 vs 13.5 +/- 2.2 cm/s; p <0.001). Pulmonary artery pressure was higher in patients compared with controls (32.1 +/- 5.4 vs 26.1 +/- 6.5 mm Hg; p <0.001). Exercise testing showed decreased exercise tolerance in HIV(+) patients, with no case of myocardial ischemia. In conclusion, subclinical cardiac abnormalities are frequently observed in HIV(+) patients on HAART. The usefulness of systematic noninvasive screening in this population should be considered. GECEM study no. 30: National Agency for AIDS Research (ANRS).


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Estudos de Casos e Controles , Diástole/fisiologia , Ecocardiografia , Teste de Esforço , Tolerância ao Exercício/fisiologia , Frequência Cardíaca/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Estudos Prospectivos , Descanso/fisiologia , Volume Sistólico/fisiologia , Sístole/fisiologia , Disfunção Ventricular Esquerda/diagnóstico por imagem
11.
Diabetes ; 55(3): 608-15, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16505222

RESUMO

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 in db/db mice. Two-photon microscopy identified intracellular calcium concentration ([Ca2+]i) transient decrease in cardiomyocytes within the whole heart, which was also found in isolated myocytes by confocal microscopy. Global [Ca2+]i transients are constituted of individual Ca2+ sparks. Ca2+ sparks in db/db cardiomyocytes were less frequent than in +/+ myocytes, partly because of a depression in sarcoplasmic reticulum Ca2+ load but also because of a reduced expression of ryanodine receptor Ca2+ channels (RyRs), revealed by [3H]ryanodine binding assay. Ca2+ efflux through Na+/Ca2+ exchanger was increased in db/db myocytes. Calcium current, I(Ca), triggers sarcoplasmic reticulum Ca2+ release and is also involved in sarcoplasmic reticulum Ca2+ refilling. Macroscopic I(Ca) was reduced in db/db cells, but single Ca2+ channel activity was similar, suggesting that diabetic myocytes express fewer functional Ca2+ channels, which was confirmed by Western blots. These results demonstrate that db/db mice show depressed cardiac function, at least in part, because of a general reduction in the membrane permeability to Ca2+. As less Ca2+ enters the cell through I(Ca), less Ca2+ is released through RyRs.


Assuntos
Cálcio/metabolismo , Cardiomiopatias/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Miocárdio/metabolismo , Animais , Canais de Cálcio Tipo L/fisiologia , Diabetes Mellitus Tipo 2/complicações , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Contração Miocárdica , Canal de Liberação de Cálcio do Receptor de Rianodina/fisiologia , Retículo Sarcoplasmático/metabolismo
12.
Blood Press Monit ; 22(2): 86-94, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27902494

RESUMO

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 flow, diameter changes, and local pulse wave velocity (PWV), while recording Korotkoff sounds 10 cm downstream together with cuff pressure and ECG. RESULTS: The systolic (SBP) and diastolic (DBP) blood pressures were 118.8±17.7 and 65.4±10.4 mmHg, respectively (n=23). The brachial artery lumen started opening when cuff pressure decreased below the SBP and opened for an increasing length of time until cuff pressure reached the DBP, and then remained open but pulsatile. A high-energy low-frequency Doppler signal, starting a few milliseconds before flow, appeared and disappeared together with Korotkoff sounds at the SBP and DBP, respectively. Its median duration was 42.7 versus 41.1 ms for Korotkoff sounds (P=0.54; n=17). There was a 2.20±1.54 ms/mmHg decrement in the time delay between the ECG R-wave and the Korotkoff sounds during cuff deflation (n=18). The PWV was 10±4.48 m/s at null cuff pressure and showed a 0.62% decrement per mmHg when cuff pressure increased (n=13). CONCLUSION: Korotkoff sounds are associated with a high-energy low-frequency Doppler signal of identical duration, typically resulting from wall vibrations, followed by flow turbulence. Local arterial PWV decreases when cuff pressure increases. Exploiting these changes may help improve SBP assessment, which remains a challenge for oscillometric techniques.


Assuntos
Pressão Sanguínea/fisiologia , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/fisiologia , Análise de Onda de Pulso , Ultrassonografia Doppler Dupla , Adulto , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
J Hypertens ; 35(5): 1002-1010, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28099195

RESUMO

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 from the foot to the apex of the systolic peak of the oscillometric signal, which reaches a maximum concomitant with the first Korotkoff sound. METHOD: In 145 study participants and patients (group 1), we measured the systolic brachial artery blood pressure by Korotkoff sound recording, conventional oscillometry, and our fully automated systolic peak foot-to-apex time interval (SFATI) technique. In 35 other patients (group 2), we compared SFATI with intra-arterial measurement. RESULTS: In group 1, the concordance correlation coefficient was 0.989 and 0.984 between SFATI and Korotkoff sounds, 0.884 and 0.917 between oscillometry and Korotkoff sounds, and 0.882 and 0.919 between SFATI and oscillometry, respectively, on the left and right arm. In group 2, it was 0.72 between SFATI and intra-arterial measurement, 0.67 between oscillometry and intra-arterial measurement, and 0.92 between SFATI and Korotkoff sounds. In 40 study participants, the reproducibility study yielded a concordance coefficient of 0.95 for SFATI and 0.94 for Korotkoff sounds. CONCLUSION: SFATI BP measurement shows an excellent concordance with the auscultatory technique, offering a major improvement over current oscillometric techniques and allowing standardization.


Assuntos
Determinação da Pressão Arterial/métodos , Pressão Sanguínea , Oscilometria , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Artéria Braquial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Padrões de Referência , Reprodutibilidade dos Testes , Sístole , Adulto Jovem
14.
J Hypertens ; 34(8): 1615-20, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27219488

RESUMO

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 arrhythmia or heart failure, were compared with 29 normotensive controls. Speckle-tracking echocardiography of the LA wall was used to measure systolic and diastolic strains and strain rates. Early diastolic velocity of transmitral flow/early diastolic mitral annular motion velocity (E/E')/peak systolic LA strain (S-LAs) was used as an index of LA stiffness. RESULTS: HTN patients had higher LV mass index, impaired LV diastolic function, and higher LA volume index than controls. LA reservoir, conduit, and booster pump functions were significantly lower and LA stiffness was greater. Multiple regression analysis indicated that increased LV mass and LV filling pressures as well as reduced LV strain or E' were predictors for reduced atrial function. CONCLUSION: HTN patients showed a significant impairment of the three components of LA function. These changes were correlated with LV hypertrophy and dysfunction, and presumably related to LA fibrotic changes, underlining the importance of LA-LV coupling. The prognostic value of these new speckle-tracking echocardiography-based LA strain indices needs to be evaluated by future studies.


Assuntos
Função do Átrio Esquerdo , Átrios do Coração/patologia , Átrios do Coração/fisiopatologia , Ventrículos do Coração/patologia , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Estudos de Casos e Controles , Diástole , Ecocardiografia , Feminino , Átrios do Coração/diagnóstico por imagem , Humanos , Hipertensão/complicações , Hipertrofia Ventricular Esquerda/complicações , Hipertrofia Ventricular Esquerda/patologia , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Análise de Regressão , Sístole
15.
Heart Rhythm ; 12(8): 1827-35, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25863159

RESUMO

BACKGROUND: Real-time monitoring of radiofrequency (RF) ablation remains challenging. OBJECTIVE: We used intravascular ultrasound (IVUS) to describe atrial wall changes during RF ablation and to assess the extent of RF-induced lesions. METHODS: In 9 piglets, RF and IVUS catheters were coupled and introduced into the right atrium. RF applications were performed along the intercaval line. Corresponding IVUS images were analyzed. Wall thickness was correlated with electrogram (EGM) changes (n = 9) and histology (n = 5). RESULTS: There were 66 RF applications performed in 57 sites. IVUS provided real-time imaging of the atrial wall during RF application in all but 2 sites. IVUS demonstrated significant (>20%) and immediate increase in atrial wall thickness in 71.4% of RF applications. It showed epicardial or intramyocardial effusion in 30% of cases, 2 steam pops, 1 intramural hematoma, and 1 thrombus. EGM amplitude decreased and thickness increased after RF application than at baseline (2.20 ± 1.11 to 0.99 ± 0.62 mV and 1.34 ± 0.53 to 1.93 ± 0.80 mm, respectively; P < .001 for each). However, EGM and thickness changes were poorly correlated (r = 0.43; P < .05). Histologically and echographically measured thicknesses were correlated (r = 0.71; P = .004), but echographic thickness change was not related to histological lesion transmurality. CONCLUSION: An IVUS probe coupled to an RF catheter can provide relevant real-time imaging of the atrial wall during ablation. Although thickness change does not appear as a good predictor of the transmural extent, direct visualization and monitoring of RF application may provide new information to guide and secure RF ablation.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Diagnóstico por Imagem/métodos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/patologia , Ultrassonografia de Intervenção/métodos , Animais , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Modelos Animais de Doenças , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas/métodos , Átrios do Coração/fisiopatologia , Suínos , Resultado do Tratamento
16.
J Am Soc Echocardiogr ; 27(11): 1208-15, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25127983

RESUMO

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 filling. On the other hand, endurance training has been shown to improve cardiac function. METHODS: Speckle-tracking echocardiography was performed in 106 endurance-trained male athletes and 75 controls (age range 18-70 years), divided into three groups according to age. RESULTS: From the younger to older age groups, progressive increases in LV apical rotation and twist angle and a decrease in LV untwisting rate during isovolumic relaxation time were observed. Athletes had lower systolic twist angles (P < .01) but higher untwist/twist ratios and LV untwisting rate during isovolumic relaxation time compared with controls, with the largest difference between senior groups (51 ± 24% vs 42 ± 22% in the young and 42 ± 29% vs 24 ± 25% in seniors, P < .001, respectively). The normal timing of untwisting rate occurring before radial displacement was preserved in athletes with increasing age, whereas it was blunted in controls. CONCLUSIONS: Endurance training does not prevent but minimizes changes in LV twist-untwist mechanics from young subjects to seniors. Athletes showed smaller increases of twist angle with age and smaller declines of LV untwisting rate during isovolumic relaxation time and untwist/twist ratio compared with controls. This training-improved preservation of LV twist-untwist mechanics is likely to play a key role for systolic-diastolic coupling and diastolic filling, particularly during exercise.


Assuntos
Ecocardiografia/métodos , Técnicas de Imagem por Elasticidade/métodos , Condicionamento Físico Humano/métodos , Resistência Física/fisiologia , Função Ventricular Esquerda/fisiologia , Adolescente , Adulto , Idoso , Módulo de Elasticidade/fisiologia , Feminino , Ventrículos do Coração , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Rotação , Sensibilidade e Especificidade , Caracteres Sexuais , Resistência ao Cisalhamento/fisiologia , Estresse Mecânico , Volume Sistólico/fisiologia , Adulto Jovem
17.
J Am Soc Echocardiogr ; 26(11): 1298-305, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23972490

RESUMO

BACKGROUND: 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. METHODS: Using speckle-tracking echocardiography, LV twist-untwist mechanics were studied in 25 children (aged 10-12 years) and 20 young adults (aged 18-44 years) at rest and during three exercise workloads performed at 20%, 30%, and 40% of their maximal aerobic power. RESULTS: At rest, LV twist was lower in children, because of a higher temporal dispersion of peak rotation between base and apex. During exercise, the increase of basal rotation was blunted in children compared with adults (-6.7 ± 2.7° vs -9.0 ± 2.0° at 40% of maximal aerobic power, P < .05). Consequently, LV twist increased to a lesser extent (13.0 ± 5.0° vs 15.8 ± 4.5° at 40% of maximal aerobic power, P < .05). The increase in LV untwisting rates during exercise was also lower in children, leading to a lower percentage of untwisting during early diastole (8 ± 8% vs 29 ± 20% at 40% of maximal aerobic power, P < .001). Consequently, during early diastole, the normal timing of diastolic events observed in young adults, with untwist occurring before radial displacement, was blunted in children. Nevertheless, children exhibited normal LV filling due to higher diastolic radial and longitudinal strain rates. CONCLUSIONS: Twist-untwist mechanics may evolve with advancing age. In children, early diastolic LV untwisting appears to be less important than in adults. Their better LV intrinsic myocardial relaxation may ensure adequate LV filling during exercise without dependence on the additional effect of suction resulting from LV energy recoil.


Assuntos
Envelhecimento/fisiologia , Ecocardiografia/métodos , Exercício Físico/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Esforço Físico/fisiologia , Função Ventricular Esquerda/fisiologia , Adolescente , Adulto , Criança , Feminino , França , Humanos , Masculino , Rotação , Adulto Jovem
18.
Med Sci Sports Exerc ; 45(11): 2072-9, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23657162

RESUMO

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 upon the completion of exercise. Therefore, the objective was to evaluate LV systolic function before and after a PSE using two-dimensional speckle tracking echocardiography not only at rest but also during incremental tests to adjust heart rates (HR). METHODS AND RESULTS: Sixteen healthy young men (23 ± 3 yr old) performed a 3-h period of intensity-controlled upright cycling. LV strain (S), systolic strain rate (SR), rotation, and systolic rotational rate were evaluated by two-dimensional speckle tracking echocardiography before and after a 3-h period of PSE at rest and during incremental tests. Posttest evaluation was performed once the HR had returned to the pretest value. Under resting conditions, parameters of systolic function were either unchanged or increased after the PSE. However, during the incremental test, all LV systolic SR and apical rotational rates were decreased after PSE (radial SR at workload 3 (W3): 2.21 ± 0.12.s(-1) vs 1.87 ± 0.10.s(-1), P < 0.01 and apical rotational rate at W3: 128 ± 28 deg.s(-1) vs 105 ± 26 deg.s(-1), P < 0.05). Regression analyses between LV systolic SR and HR showed lower y-intercepts without differences in slopes, suggesting a decrease of both global and regional systolic functions irrespective of HR after the PSE. CONCLUSION: Our findings based on LV S and SR data during incremental tests demonstrate that the 3-h period of PSE induces LV systolic dysfunction.


Assuntos
Ciclismo/fisiologia , Esforço Físico/fisiologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Ecocardiografia , Frequência Cardíaca , Humanos , Masculino , Descanso/fisiologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Adulto Jovem
19.
Obesity (Silver Spring) ; 20(1): 134-40, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21869756

RESUMO

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 without concomitant diet. Cardiac function and myocardial synchrony were assessed by echocardiography with tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). At baseline, obese men showed diastolic dysfunction on standard echocardiography, lower strain values (systolic strain: 15.9 ± 0.9 vs. 18.8 ± 0.3%, diastolic strain rate: 0.81 ± 0.09 vs. 1.05 ± 0.06 s(-1)), and significant intraventricular dyssynchrony (systolic: 13.3 ± 2.1 vs. 5.4 ± 2.1 ms, diastolic: 17.4 ± 3.2 vs. 9.1 ± 2.1 ms) (P < 0.05 vs. controls for all variables). Training improved aerobic fitness, decreased systolic blood pressure and heart rate, and reduced fat mass without weight loss. Diastolic function, strain values (systolic strain: 17.4 ± 0.9%, diastolic strain rate: 0.96 ± 0.12 s(-1)) and intraventricular dyssynchrony (systolic: 3.3 ± 1.7 ms, diastolic: 5.5 ± 3.4 ms) improved significantly after training (P < 0.05 vs. baseline values for all variables), reaching levels similar to those of normal-weight men. In conclusion, in obese men, a short and easy-to-perform low intensity training program restored diastolic function and cardiac synchrony and improved body composition without weight loss.


Assuntos
Ecocardiografia Doppler em Cores , Eletrocardiografia , Hipertrofia Ventricular Esquerda/fisiopatologia , Obesidade/fisiopatologia , Treinamento Resistido/métodos , Adulto , Análise de Variância , Débito Cardíaco , Diástole , Humanos , Hipertrofia Ventricular Esquerda/reabilitação , Masculino , Pessoa de Meia-Idade , Obesidade/reabilitação , Estudos Prospectivos , Resultado do Tratamento
20.
Circ Cardiovasc Imaging ; 5(3): 324-32, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22414888

RESUMO

BACKGROUND: 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. METHODS AND RESULTS: Twenty nonobstructive HCM patients (age, 48.3±12.3 years; 14 men) and 20 control subjects underwent speckle-tracking echocardiographic measurement of longitudinal, radial, and circumferential strains, systolic twist, and diastolic untwisting rate (UTR) at rest and submaximal exercise. HCM patients showed lower resting longitudinal (-15.7±5.0% versus -19.4±2.6%, P<0.001) and radial (38.1±11.3% versus 44.7±14.4%, P<0.05) strains but higher circumferential strain (-21.9±4.0% versus -18.8±2.3%, P<0.05) and twist (15.7±3.6° versus 9.3±2.6°, P<0.0001) than control subjects. Exercise induced an increase in all strains in control subjects but only a moderate increase in longitudinal strain (to -18.4±5.0%), without significant changes in radial and circumferential strains or twist in HCM patients. Exercise peak UTR was lower (-119.0±31.5°/s versus -137.3±41.1°/s) and occurred later (137±18% versus 125±11% systolic time, P<0.05) in HCM than in control subjects. A significant relationship between twist and UTR was obtained in control subjects (ß=-0.0807, P<0.001) but not in HCM patients (ß=-0.0051, P=0.68). CONCLUSIONS: HCM patients had severely limited strain adaptability and no LV twisting reserve at exercise. They had reduced and delayed UTR with reduced systolic-diastolic coupling efficiency by twist-untwist mechanics.


Assuntos
Cardiomiopatia Hipertrófica/complicações , Cardiomiopatia Hipertrófica/fisiopatologia , Exercício Físico , Anormalidade Torcional/complicações , Anormalidade Torcional/diagnóstico por imagem , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem , Análise de Variância , Diástole , Teste de Esforço/métodos , Feminino , Ventrículos do Coração/anormalidades , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Descanso , Sístole , Fatores de Tempo , Anormalidade Torcional/fisiopatologia , Ultrassonografia , Disfunção Ventricular Esquerda/fisiopatologia
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