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Background: Several sex-specific risk factors (SS-RFs) increase a women's risk for cardiovascular disease (CVD) but are often overlooked during risk assessment. The purpose of this study was to identify the prevalence of SS-RFs and assess CVD risk, knowledge, perceptions and behaviours in premenopausal Canadian women. Methods: An online survey was distributed across Canada to premenopausal biological females (19-49 years of age). The survey gathered demographics, medical history, engagement in health-promoting behaviours, and knowledge and perceptions of CVD risk. CVD risk was calculated using medical risk and SS-RFs were tabulated from medical history. Results: A total of 2559 participants (33 ± 8 years) completed the survey. The majority of our sample (82%) was classified as low medical risk. Of those classified as low risk, 35% had at least 1 SS-RF. Of high-risk individuals, 70% underestimated their risk, 21% of whom perceived themselves as low risk. Engagement in health behaviours was suboptimal. Knowledge of traditional CVD risk factors and prevention was relatively high; however, less than one-half were aware of SS-RFs such as early menopause (39.4%). Conclusions: Considering both traditional and SS-RFs, 47% of premenopausal Canadian women may be at risk for developing CVD. Of those deemed low medical risk for developing CVD, more than one-third reported having at least 1 SS-RF. Canadian women have poor knowledge of the risks associated with SS-RFs, lack sufficient awareness of the need for prevention of CVD, and are not engaging in sufficient health-promoting behaviours to mitigate future CVD risk.
Contexte: Plusieurs facteurs de risque liés au sexe (FR-LS) font augmenter le risque de maladies cardiovasculaires (MCV) chez les femmes, mais sont souvent négligés durant l'évaluation des risques. L'objectif de la présente étude était de déterminer la prévalence des FR-LS et d'évaluer le risque de MCV, les connaissances, les perceptions et les comportements au sein des femmes canadiennes préménopausées. Méthodes: Une enquête en ligne a été distribuée aux femmes biologiques préménopausées (19-49 ans) du Canada. L'enquête a permis de recueillir les données démographiques, les antécédents médicaux, les renseignements sur l'adoption de comportements favorisant la santé, les connaissances et les perceptions du risque de MCV. Le risque de MCV a été calculé à partir du risque médical, et les FR-LS, compilés à partir des antécédents médicaux. Résultats: Un total de 2 559 participantes (33 ± 8 ans) ont rempli l'enquête. La majorité de notre échantillon (82 %) a été classifiée dans la catégorie de faible risque médical. Parmi celles classifiées dans la catégorie de faible risque, 35 % avaient au moins 1 FR-LS. Parmi les personnes exposées à un risque élevé, 70 % sous-estimaient leur risque, et 21 % parmi elles se percevaient exposées à un faible risque. L'adoption de comportements liés à la santé était sous-optimale. Les connaissances sur les facteurs de risque de MCV traditionnels et sur la prévention étaient relativement élevées. Toutefois, moins de la moitié connaissaient les FR-LS telle la ménopause précoce (39,4 %). Conclusions: Si l'on tient compte des FR traditionnels et des FR-LS, 47 % des femmes canadiennes préménopausées sont exposées au risque d'avoir une MCV. Parmi celles jugées à faible risque médical de MCV, plus d'un tiers ont déclaré avoir au moins 1 FR-LS. Les femmes canadiennes connaissent peu les risques associés aux FR-LS, ne disposent pas d'informations suffisantes sur la nécessité de la prévention des MCV, et n'adoptent pas suffisamment de comportements favorisant la santé pour atténuer le risque futur de MCV.
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AIMS: Detraining refers to a loss of training adaptations resulting from reductions in training stimulus due to illness, injury, or active recovery breaks in a training cycle and is associated with a reduction in left ventricular mass (LVM). The purpose of this study was to conduct a systematic review and meta-analysis to determine the influence of detraining on LVM in endurance-trained, healthy individuals. METHODS AND RESULTS: Using electronic databases (e.g. EMBASE and MEDLINE), a literature search was performed looking for prospective detraining studies in humans. Inclusion criteria were adults, endurance-trained individuals with no known chronic disease, detraining intervention >1 week, and pre- and post-detraining LVM reported. A pooled statistic for random effects was used to assess changes in LVM with detraining. Fifteen investigations (19 analyses) with a total of 196 participants (ages 18-55 years, 15% female) met inclusion criteria, with detraining ranging between 1.4 and 15 weeks. The meta-analysis revealed a significant reduction in LVM with detraining (standardized mean difference = -0.586; 95% confidence interval = -0.817, -0.355; P < 0.001). Independently, length of detraining was not correlated with the change in LVM. However, a meta-regression model revealed length of the detraining, when training status was accounted for, was associated with the reduction of LVM (Q = 15.20, df = 3, P = 0.0017). Highly trained/elite athletes had greater reductions in LVM compared with recreational and newly trained individuals (P < 0.01). Limitations included relatively few female participants and inconsistent reporting of intervention details. CONCLUSION: In summary, LVM is reduced following detraining of one week or more. Further research may provide a greater understanding of the effects of sex, age, and type of detraining on changes in LVM in endurance-trained individuals.
In healthy, endurance-trained individuals, detraining results in significant reductions in left ventricular mass. When accounting for training status, the length of the detraining period is positively associated with reductions in left ventricular mass. Limited research on this topic hinders the ability to assess sex differences or the impact of the type of detraining (i.e. only activities of daily living vs. reduced training load) on the response to detraining.
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Treino Aeróbico , Função Ventricular Esquerda , Humanos , Atletas , Resistência Física , Estudos ProspectivosRESUMO
Background: The impact of the menstrual phases on left ventricular (LV) structure and function using 3D echocardiography and resting electrocardiogram (ECG) in healthy, eumenorrheic, and physically active females has not been investigated. Methods: sixteen females (20 y ± 2) underwent 3D echocardiography and an ECG at three time points in the menstrual cycle phases (follicular, ovulation, luteal). LV end-diastolic volume (LVEDVi), LV ejection fraction (LVEF), LV mass allometrically indexed to height2.7 (LVMi), torsion, and global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS) were evaluated. ECG data of the P and QRS waves were presented as well as axis deviation, chamber enlargement, and any rhythm abnormalities. Results: LVMi was significantly higher in the luteal phase (36.4 g/m2.7 ± 3.3) compared to the follicular (35.0 g/m2.7 ± 3.7) and ovulation (34.7 g/m2.7 ± 4.3) phases (p = 0.026). There were no differences in other indices of LV structure and function or ECG variables across all phases of the menstrual cycle or evidence of arrhythmia. Conclusions: In physically active females, there is a small but significantly higher LVMi associated with the luteal phase of the menstrual cycle with no concomitant change in LV function or ECG parameters. These findings are important to consider when conducting clinical or research serial assessments.
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AIMS: To determine the impact of endurance training (ET) interventions on left ventricular (LV) chamber size, wall thickness, and mass in healthy adults. METHODS AND RESULTS: Electronic databases including CINAHL, MEDLINE, PsycINFO, SPORTDiscus, Cochrane library, and EBM Reviews were searched up to 4 January 2022. Criteria for inclusion were healthy females and/or males (>18 years), ET intervention for ≥2 weeks, and studies reporting pre- and post-training LV structural parameters. A random-effects meta-analysis with heterogeneity, publication bias, and sensitivity analysis was used to determine the effects of ET on LV mass (LVM) and diastolic measures of interventricular septum thickness (IVSd), posterior wall thickness (PWTd), and LV diameter (LVDd). Meta-regression was performed on mediating factors (age, sex, training protocols) to assess their effects on LV structure. Eighty-two studies met inclusion criteria (n = 1908; 19-82 years, 33% female). There was a significant increase in LVM, PWTd, IVSd, and LVDd following ET [standardized mean difference (SMD) = 0.444, 95% confidence interval (CI): 0.361, 0.527; P < 0.001; SMD = 0.234, 95% CI: 0.159, 0.309; P < 0.001; SMD = 0.237, 95% CI: 0.159, 0.316; P < 0.001; SMD = 0.249, 95% CI:0.173, 0.324; P < 0.001, respectively]. Trained status, training type, and age were the only mediating factors for change in LVM, where previously trained, mixed-type training, young (18-35 years), and middle-aged (36-55 years) individuals had the greatest change compared with untrained, interval-type training, and older individuals (>55 years). A significant increase in wall thickness was observed in males, with a similar augmentation of LVDd in males and females. Trained individuals elicited an increase in all LV structures and ET involving mixed-type training and rowing and swimming modalities conferred the greatest increase in PWTd and LVDd. CONCLUSION: Left ventricular structure is significantly increased following ET. Males, young and trained individuals, and ET interventions involving mixed training regimes elicit the greatest changes in LV structure.
Heart structure significantly increases the following endurance training (ET) ≥2 weeks.Changes in heart structure were most prominent in males, who are young (1835 years), already trained, and following concurrent continuous and interval training.Changes in heart size were not shown in older individuals (>55 years) compared with young and middle-aged individuals.While both males and females similarly increase their cavity size and heart mass, sex differences were revealed for wall thickness where significant increases were seen in males but not females.
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Treino Aeróbico , Masculino , Pessoa de Meia-Idade , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Ventrículos do Coração/diagnóstico por imagem , Terapia por Exercício , Natação , Resistência Física , Função Ventricular EsquerdaRESUMO
Sleep hygiene practices may hinder university athletes from obtaining quality sleep to support health and performance. We sought to provide a comprehensive evaluation of sleep quality and behaviors in varsity athletes using validated sleep questionnaires: the Athlete Sleep Screening Questionnaire (ASSQ) and the Athlete Sleep Behavior Questionnaire (ASBQ). Sixty-four (n = 64) athletes participated (54% female; 71% Caucasian). The mean age was 20.3 ± 1.7 years and the mean BMI was 23.3 ± 3.3. Fifty-one percent met the threshold for adequate sleep (7+ h) and 54% reported being somewhat/very satisfied with sleep quality. Global scores for ASSQ Sleep Difficulty and ASBQ sleep behaviors were significantly correlated (r = 0.31; p = 0.014) and not significantly different across age, academic year, or residence. According to the ASSQ, 11% and 24% were classified as having severe or moderate sleep problems, respectively. The ASBQ categorized 62% as having "poor" sleep behaviors. Notable sleep-influencing factors included a high frequency of emotional/cognitive processing of sport-performance issues (46.9%), frequent use of light-emitting devices before bed (90%), training after 7 pm (65%), and the use of sleep medication (19%). Half of the university athletes did not meet the thresholds for adequate sleep, and some may require a referral for clinical sleep issues. The majority of these athletes' sleep behaviors do not promote adequate sleep. The ASSQ shows utility to assess gradations in clinical sleep difficulty; the ASBQ could be used in concert with the ASSQ to discern "cognitive and physiological arousal" targets for use in educational workshops designed to promote optimal sleep hygiene in university athletes.
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BACKGROUND: Chronic endurance exercise training elicits desirable physiological adaptations in the cardiovascular system. The volume of exercise training required to generate healthy adaptations is unclear. This study assessed the effects of differing exercise training levels on arterial stiffness, compliance, and autonomic function. METHODS: Eighty healthy adults (38.5 ± 9.7 years; 44% female) defined as endurance-trained (ET, n = 29), normally active (NA, n = 27), or inactive (IN, n = 24) participated. Cardiovascular markers, including hemodynamics, large arterial compliance and small arterial compliance (LAC and SAC), carotid-femoral pulse wave velocity (PWV), and spontaneous baroreceptor sensitivity (BRS) were assessed. RESULTS: ET showed significantly greater LAC values (21.4 ± 6.5) than NA (16.9 ± 2.5; p = 0.002) and IN (14.7 ± 3.2 mL × mm Hg × 10; p = 0.028). Values for SAC and BRS were significantly higher in ET than IN (p < 0.001 and p = 0.028, respectively), but not NA. Compared to IN, PWV values for ET and NA were significantly lower (p < 0.003). After adjusting for covariates (age, sex, and SBP), significant associations with cardiovascular fitness status were noted for all markers but BRS. CONCLUSION: Endurance exercise increases LAC likely due to high-volume training; however, lower volumes of physical activity may be sufficient to positively benefit vascular health overall.
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Artérias/fisiologia , Barorreflexo , Aptidão Cardiorrespiratória , Hemodinâmica , Rigidez Vascular , Adaptação Fisiológica , Adulto , Pressão Sanguínea , Estudos Transversais , Exercício Físico , Feminino , Voluntários Saudáveis , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física , Fatores Sexuais , Adulto JovemRESUMO
INTRODUCTION: Pediatric heart transplant (HTx) recipients have reduced exercise capacity typically two-thirds of predicted values, the mechanisms of which are not fully understood. We sought to assess the cardiorespiratory responses to progressive exercise in HTx relative to controls matched for age, sex, body size, and work rate. METHODS: Fourteen HTx recipients and matched controls underwent exercise stress echocardiography on a semisupine cycle ergometer. Hemodynamics, left ventricular (LV) dimensions, and volumes were obtained and indexed to body surface area. Oxygen consumption (VËO2) was measured, and arteriovenous oxygen difference was estimated using the Fick Principle. RESULTS: At rest, LV mass index (P = 0.03) and volumes (P < 0.001) were significantly smaller in HTx, whereas wall thickness (P < 0.01) and LV mass-to-volume ratio (P = 0.01) were greater. Differences in LV dimensions and stroke volume persisted throughout exercise, but the pattern of response was similar between groups as HR increased. As exercise progressed, heart rate and cardiac index increased to a lesser extent in HTx. Despite this, VËO2 was similar (P = 0.82) at equivalent work rates as HTx had a greater change in arteriovenous oxygen difference (P < 0.01). CONCLUSIONS: When matched for work rate, HTx had similar metabolic responses to controls despite having smaller LV chambers and an attenuated increase in hemodynamic responses. These findings suggest that HTx may increase peripheral O2 extraction as a compensatory mechanism in response to reduced cardiovascular function.
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Exercício Físico/fisiologia , Transplante de Coração , Consumo de Oxigênio , Adolescente , Estudos de Casos e Controles , Criança , Ecocardiografia , Teste de Esforço , Feminino , Frequência Cardíaca , Hemodinâmica , Humanos , Masculino , Estudos Retrospectivos , Volume Sistólico , Transplantados , Função Ventricular EsquerdaRESUMO
OBJECTIVE: Pediatric heart transplant recipients are at risk of posttransplant coronary artery disease known as cardiac allograft vasculopathy (CAV), and also may develop diastolic dysfunction. As CAV begins with a process of progressive intimal thickening, these occult diffuse changes may be detected using optical coherence tomography (OCT). We hypothesized that the development of CAV, as identified via OCT, may be a mechanism of declining ventricular function. Accordingly, the purpose of this study was to assess coronary artery intimal thickening and LV strain in children who have undergone heart transplantation. METHODS: In 17 children, we analyzed OCT images for coronary intima and media thickness, and cross-sectional area (CSA). We also performed speckle tracking imaging (STI) of the LV to determine longitudinal strain and strain rate, in addition to standard echocardiographic measures. RESULTS: Longitudinal diastolic strain rate was associated with maximum intima thickness (r = -.497, P = .042), intima CSA, (r = -.489, P = .047), maximum media thickness (r = -.503, P = .039), and media CSA (r = -.614, P = .009). The intima maximum thickness, intima/media, and intima/lumen ratios were associated with stroke volume index (Std. ß = -0.487, P = .023 and Std. ß = -0.488, P = .022, respectively). CONCLUSIONS: These findings suggest coronary artery intimal thickening may be mechanistically linked to changes in ventricular function following cardiac transplantation.
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Doença da Artéria Coronariana/diagnóstico , Vasos Coronários/diagnóstico por imagem , Ecocardiografia Doppler/métodos , Transplante de Coração/efeitos adversos , Ventrículos do Coração/fisiopatologia , Tomografia de Coerência Óptica/métodos , Função Ventricular Esquerda/fisiologia , Adolescente , Criança , Angiografia Coronária/métodos , Doença da Artéria Coronariana/etiologia , Feminino , Seguimentos , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Estudos Retrospectivos , Volume Sistólico/fisiologia , TransplantadosRESUMO
Heart transplant recipients are at increased risk for atherosclerosis and cardiac allograft vasculopathy, both initially presenting as intimal thickening. We aimed to determine the presence, extent, and anatomical characteristics of intimal thickness at coronary bifurcations in children using OCT. We measured the intimal thickness of coronary arteries in pediatric transplant recipients using OCT during routine cardiac catheterization. Intimal thickening was defined as (i) a percent change in contralateral intimal thickness greater than 50% when comparing the thickness at the bifurcation to the baseline thickness, and (ii) greater than 0.1 mm. We evaluated 153 unique coronary bifurcations in 31 children (58% boys, median 12.7 years). Intimal thickening was almost exclusively observed in the left coronary system (22 of 67 bifurcations) and rare in the right coronary system (2 of 86 bifurcations; P < .001). There was a positive association between the relative size of the side branch and contralateral intimal thickening at coronary bifurcations (P = .009). Intimal thickening at coronary bifurcations is already present in the left coronary system in many pediatric transplant recipients. The correlation between intimal thickening and side branch size suggests that low shear stress and oscillating shear stress may have an important role in the development of intimal thickening at coronary bifurcations.
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Vasos Coronários/patologia , Transplante de Coração , Tomografia de Coerência Óptica , Túnica Íntima/patologia , Adolescente , Criança , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/patologia , Vasos Coronários/diagnóstico por imagem , Estudos Transversais , Feminino , Humanos , Masculino , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Fatores de Risco , Túnica Íntima/diagnóstico por imagemRESUMO
Early detection of hemorrhage remains an open problem. In this regard, blood pressure has been an ineffective measure of blood loss due to numerous compensatory mechanisms sustaining arterial blood pressure homeostasis. Here, we investigate the feasibility of causality detection in the heart rate and blood pressure interaction, a closed-loop control system, for early detection of hemorrhage. The hemorrhage was simulated via graded lower-body negative pressure (LBNP) from 0 to -40 mmHg. The research hypothesis was that a significant elevation of causal control in the direction of blood pressure to heart rate (i.e., baroreflex response) is an early indicator of central hypovolemia. Five minutes of continuous blood pressure and electrocardiogram (ECG) signals were acquired simultaneously from young, healthy participants (27 ± 1 years, N = 27) during each LBNP stage, from which heart rate (represented by RR interval), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were derived. The heart rate and blood pressure causal interaction (RRâSBP and RRâMAP) was studied during the last 3 min of each LBNP stage. At supine rest, the non-baroreflex arm (RRâSBP and RRâMAP) showed a significantly (p < 0.001) higher causal drive toward blood pressure regulation compared to the baroreflex arm (SBPâRR and MAPâRR). In response to moderate category hemorrhage (-30 mmHg LBNP), no change was observed in the traditional marker of blood loss i.e., pulse pressure (p = 0.10) along with the RRâSBP (p = 0.76), RRâMAP (p = 0.60), and SBPâRR (p = 0.07) causality compared to the resting stage. Contrarily, a significant elevation in the MAPâRR (p = 0.004) causality was observed. In accordance with our hypothesis, the outcomes of the research underscored the potential of compensatory baroreflex arm (MAPâRR) of the heart rate and blood pressure interaction toward differentiating a simulated moderate category hemorrhage from the resting stage. Therefore, monitoring baroreflex causality can have a clinical utility in making triage decisions to impede hemorrhage progression.
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OBJECTIVES: The aim of this study was to systematically evaluate the incidence of infective endocarditis (IE) in right ventricle-to-pulmonary artery conduits and valves, comparing bovine jugular vein (BJV) valves with all others. BACKGROUND: Recent evidence suggests that the incidence of IE is higher in patients with congenital heart disease who have undergone implantation of BJV valves in the pulmonary position compared with other valves. METHODS: Systematic searches of published research were conducted using electronic databases (MEDLINE, Embase, and CINAHL) and citations cross-referenced current to April 2016. Included studies met the following criteria: patients had undergone right ventricle-to-pulmonary artery conduit or percutaneous pulmonary valve implantation, and investigators reported on the type of conduit or valve implanted, method of intervention (surgery or catheter based), IE incidence, and follow-up time. RESULTS: Fifty studies (Levels of Evidence: 2 to 4) were identified involving 7,063 patients. The median cumulative incidence of IE was higher for BJV compared with other valves (5.4% vs. 1.2%; p < 0.0001) during a median follow-up period of 24.0 and 35.5 months, respectively (p = 0.03). For patients with BJV valves, the incidence of IE was not different between surgical and catheter-based valve implantation (p = 0.83). CONCLUSIONS: There was a higher incidence of endocarditis with BJV valves than other types of right ventricle-to-pulmonary artery conduits. There was no difference in the incidence of endocarditis between catheter-based bovine valves and surgically implanted bovine valves, suggesting that the substrate for future infection is related to the tissue rather than the method of implantation.
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Bioprótese/efeitos adversos , Endocardite/epidemiologia , Cardiopatias Congênitas/cirurgia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas/efeitos adversos , Veias Jugulares/transplante , Infecções Relacionadas à Prótese/epidemiologia , Valva Pulmonar/cirurgia , Válvulas Venosas/transplante , Adolescente , Adulto , Aloenxertos , Animais , Bovinos , Criança , Pré-Escolar , Endocardite/diagnóstico , Feminino , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/fisiopatologia , Xenoenxertos , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Razão de Chances , Desenho de Prótese , Infecções Relacionadas à Prótese/diagnóstico , Valva Pulmonar/fisiopatologia , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Stress echocardiography has been advocated for the detection of abnormal myocardial function and unmasking diminished myocardial reserve in pediatric patients. The aim of this study was to create a simplified index of myocardial reserve, derived from the myocardial inotropic response to peak semisupine exercise in healthy children, and illustrate its applicability in a sample of pediatric oncology patients. METHODS: In this prospective analysis, children (7-18 years of age) with normal cardiac structure and function performed semisupine stress echocardiography to volitional fatigue. The quotient of wall stress at peak systole and heart rate-corrected velocity of circumferential fiber shortening were calculated at baseline and at peak exercise, the difference of which was termed the index of myocardial reserve (IMR). The IMR was also calculated in a retrospective sample of pediatric oncology patients with normal resting left ventricular function who had received anthracycline treatment and had performed the same exercise protocol to illustrate utility. RESULTS: Fifty healthy subjects (mean age, 13.2 ± 2.6 years) and 33 oncology patients (mean age, 12.7 ± 4.0 years) were assessed. In the healthy children at peak exercise, heart rate-corrected velocity of circumferential fiber shortening significantly increased (from 1.17 ± 0.17 to 1.58 ± 0.24 circ · sec-1, P < .001), while the quotient of wall stress at peak systole significantly decreased (from 75.3 ± 17.1 to 55.3 ± 13.8 g · cm-2, P < .001), shifting the plot of the relationship between the two parameters upward and to the left. The mean IMR was -30.8 ± 17.8, and the normal distribution ranged from -4.7 (fifth percentile) to -67.3 (95th percentile). The IMR was abnormal in 10 oncology patients who were treated with anthracyclines. CONCLUSIONS: The authors have developed a novel IMR. Relative to the normal distribution of this IMR in healthy subjects, it is possible to identify patients with abnormal myocardial reserve. Thus, this study demonstrates the application of the IMR to aid in clinical decision making in individual patients.
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Ecocardiografia Doppler/métodos , Ecocardiografia sob Estresse/métodos , Exercício Físico/fisiologia , Contração Miocárdica/fisiologia , Postura/fisiologia , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Valores de Referência , SístoleRESUMO
OBJECTIVE: Childhood obesity is associated with risk factors for cardiovascular disease. Arterial stiffness is considered one of the earliest detectable measures of vascular damage. There is controversy in the literature regarding the effects of childhood obesity on arterial stiffness. The objective of this study is to systematically review the literature and to conduct a meta-analysis comparing measures of central arterial stiffness in children and adolescents with obesity to healthy body mass index controls. APPROACH AND RESULTS: Literature searches were conducted using databases (eg, MEDLINE, EMBASE) and citations cross-referenced. Studies assessing central pulse wave velocity or ß-stiffness index were included. A random effects meta-analysis of the standardized mean difference and 95% confidence intervals in arterial stiffness between children with obesity and control children was performed for each arterial stiffness measure. A total of 523 studies were identified. Fifteen case-control studies were included, with 2237 children/adolescents (1281 with obesity, 956 healthy body mass index controls) between 5 and 24 years of age. All studies measuring carotid and aortic ß-stiffness index and 10/12 studies measuring central pulse wave velocity reported greater arterial stiffness in children/adolescents with obesity compared with controls. A random effects meta-analysis was performed revealing a significant effect of obesity on pulse wave velocity (standardized mean difference=0.718; 95% confidence interval=0.291-1.415), carotid ß-stiffness index (0.862; 0.323-1.402), and aortic ß stiffness index (1.017; 0.419-1.615). CONCLUSION: These findings indicate that child/adolescent obesity is associated with greater arterial stiffness. However, further research is needed to address confounders, such as pubertal status, that may affect this relationship in children. In the future, these techniques may be useful in risk stratification and guiding clinical management of obese children to optimize cardiovascular outcomes.
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Doenças Cardiovasculares/fisiopatologia , Obesidade Infantil/fisiopatologia , Rigidez Vascular , Adolescente , Fatores Etários , Índice de Massa Corporal , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Razão de Chances , Obesidade Infantil/diagnóstico , Obesidade Infantil/epidemiologia , Valor Preditivo dos Testes , Análise de Onda de Pulso , Medição de Risco , Fatores de Risco , Adulto JovemRESUMO
OBJECTIVE: To evaluate sex differences in left ventricular (LV) function after an ultramarathon, and the association of vascular and training indices with the magnitude of exercise-induced cardiac fatigue. DESIGN: Descriptive field study. SETTING: Fat Dog 100 Ultramarathon Trail Race, Canada. PARTICIPANTS: Thirty-four (13 women) recreational runners (aged 28-56 years). INTERVENTIONS: A 100-km or 160-km mountain marathon. MAIN OUTCOME MEASURES: Baseline baroreceptor sensitivity, heart rate variability, and arterial compliance; Pre-exercise and postexercise echocardiographic evaluations of LV dimensions, volumes, Doppler flow velocities, tissue velocities, strain, and strain rate. RESULTS: Finishers represented 17 men (44.8 ± 6.6 years) and 8 women (45.9 ± 10.2 years; P = 0.758). After ultraendurance exercise, significant reductions (P < 0.05) in fractional shortening (men: 40.9 ± 6.9 to 34.1 ± 7.6%; women: 42.5 ± 6.5 to 34.6 ± 7.9%) diastolic filling (E/A, men: 1.28 ± 0.68 to 1.26 ± 0.33; women: 1.55 ± 0.51 to 1.30 ± 0.27), septal and lateral tissue velocities (E'), and longitudinal strain (men: -21.02 ± 1.98 to -18.44 ± 0.34; women: -20.28 ± 1.90 to -18.44 ± 2.34) were observed. Sex differences were found for baseline cardiac structure and global function, peak late transmitral flow velocity, and estimates of LV filling pressures (P < 0.05). Regression analysis found that higher baseline arterial compliance was associated with lower reductions in cardiac function postexercise, to which sex was a significant factor for E' of the lateral wall. Faster race pace and greater lifetime ultramarathons were associated with lower reductions in LV longitudinal strain (P < 0.05). CONCLUSIONS: Cardiac responses after an ultramarathon were similar between men and women. Greater evidence of exercise-induced cardiac fatigue was found to be associated with lower baseline arterial compliance and training status/experience. CLINICAL RELEVANCE: These findings suggest that vascular health is an important contributor to the degree of cardiovascular strain incurred as the result of an acute bout of prolonged strenuous exercise.
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Coração/fisiologia , Corrida/fisiologia , Caracteres Sexuais , Adulto , Barorreflexo , Vasos Sanguíneos/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física , Função Ventricular EsquerdaRESUMO
PURPOSE: An acute reduction in blood pressure observed after a single bout of exercise is termed post-exercise hypotension (PEH). In contrast to moderate intensity aerobic exercise, little is known about the PEH response following high-intensity interval exercise. The present purpose is to assess how sex and training status impact PEH following high-intensity interval exercise. METHODS: Cardiac volumes and function via echocardiography were measured in 40 normotensive, endurance-trained (ET) and normally active (NA) men and women (Age ± SD = 30.5 ± 5.7) following high-intensity interval cycle exercise. Continuous measurements of ECG and beat-by-beat blood pressure were collected before and 30 min post-exercise for determination of cardiovagal baroreflex function (BRS and αLF), spectral analysis of heart rate and systolic blood pressure (SBP LF). RESULTS: Post-exercise systolic BP was significantly reduced from baseline, occurring to a greater degree in ET compared with NA (-12.9 vs. -5.3 mmHg, P = 0.008), while mean arterial pressure was similarly reduced in all groups (-4.6 mmHg, P = 0.003). Despite reduced SVI and TPRI, CI was increased post-exercise (P < 0.01). ET experienced a greater decrease in αLF (P = 0.037) and increase in SBP LF (P = 0.017) than NA. Lean body mass was a significant predictor of change in SBP LF (Std. ß = 0.735, P = 0.008). CONCLUSIONS: These results characterize greater depressions in cardiovagal baroreflex function, and increased sympathetic activity, following vigorous exercise in endurance-trained individuals compared with normally active participants. This heightened sympathovagal balance after high-intensity exercise may be a compensatory mechanism in response to greater peripheral blood flow demands following vigorous exercise.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Exercício Físico , Hipotensão Pós-Exercício/fisiopatologia , Adulto , Barorreflexo , Pressão Sanguínea , Feminino , Humanos , Masculino , Fatores SexuaisRESUMO
Second-generation antipsychotic (SGA) medications, used to treat youth for a wide-range of mental health conditions, are associated with excessive weight gain and other comorbidities, placing these individuals at high risk for cardiovascular disease. Little is known about the effect of physical activity (PA) on cardiovascular risk in these children. Anthropometrics, fasting blood sample and self-report PA were obtained in 386 children diagnosed with mental health conditions (6-18 y). PA was classified as below (<60 min/day) or meets (≥60 min/day) current recommended guidelines for daily PA in children. SGA-treated (n = 166) and SGA-naïve (n = 220) were compared in the analysis. The SGA-treated children had higher (p < .05) BMI z-score, waist-to-height ratio, fasting glucose, and LDL-cholesterol than SGA-naïve children. Waist circumference, waist-to-height ratio, HDL cholesterol, fasting insulin, and HOMA-IR were significantly different by PA status. After adjusting for SGA-treatment duration, sex, age, and ethnicity, higher PA was associated with lower insulin resistance (HOMA-IR) in SGA-treated (mean, 95% CI; below vs. meets: 2.10 [1.84, 2.37] vs. 1.59 [1.37, 1.81], p = .046) but not in SGA-naïve (1.70 [1.47, 1.94] vs. 1.55 [1.35, 1.75], p = .707) children. Upon initial screening, SGA-treated children that reported meeting the minimal recommendations for daily PA displayed lower measures of adiposity and improved insulin resistance.
Assuntos
Antipsicóticos/efeitos adversos , Resistência à Insulina , Atividade Motora , Adolescente , Glicemia , Índice de Massa Corporal , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Feminino , Humanos , Insulina/sangue , Masculino , Obesidade/sangue , Triglicerídeos/sangue , Circunferência da Cintura , Razão Cintura-EstaturaRESUMO
OPINION STATEMENT: Childhood obesity is associated with progressive vascular dysfunction as manifest by arterial stiffness and elevated blood pressure with associated subsequent morbidity and mortality because of early cardiovascular events including myocardial infarction and stroke in adulthood. Consequently, the recent dramatic increases in childhood obesity around the world present a hitherto unforeseen public health concern. While coordinated primary prevention efforts remain an ongoing important focus of action, identification and treatment of modifiable cardiovascular risk factors in pediatric patients is necessary given the existing burden of disease and future health consequences. Lifestyle interventions remain a cornerstone of our therapeutic approach, however, medical therapy is needed in some cases and should not be underutilized based on patient age. Herein, we discuss the relationship between childhood obesity and hypertension with a key emphasis on the evolution of adaptive and maladaptive vascular changes in the genesis of overt cardiovascular disease.
RESUMO
Altered autonomic function has been identified following ultra-endurance event participation among elite world-class athletes. Despite dramatic increases in recreational athlete participation in these ultra-endurance events, the physiological effects on these athletes are less known. This investigation sought to characterise changes in surrogate measures of autonomic function: heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) following ultra-endurance race participation. Further, we sought to compare baseline measures among ultra-endurance athletes and recreationally active controls not participating in the ultra-endurance race. Recreational ultra-endurance athletes (n = 25, 44.6 ± 8.2 years, 8 females) and recreationally active age, sex and body mass index matched controls (n = 25) were evaluated. Measurements of HRV, BPV and BRS were collected pre- and post-race for recreational ultra-endurance athletes and at baseline, for recreationally active controls. Post-race, ultra-endurance athletes demonstrated significantly greater sympathetic modulation [low frequency (LF) power HRV: 50.3 ± 21.6 normalised units (n.u.) to 65.9 ± 20.4 n.u., p = 0.01] and significantly lower parasympathetic modulation [high frequency (HF) power HRV: 45.0 ± 22.4 n.u. to 23.9 ± 13.1 n.u., p < 0.001] and BRS. Baseline measurements BRS (spectral: 13.96 ± 10.82 ms·mmHg(-1) vs. 11.39 ± 5.33 ms·mmHg(-1)) were similar among recreational ultra-endurance athletes and recreationally active controls, though recreational ultra-endurance athletes demonstrated greater parasympathetic modulation of some HRV and BPV measures. Recreational ultra-endurance athletes experienced increased sympathetic tone and declines in BRS post-race, similar to previously reported elite world-class ultra-endurance athletes, though still within normal population ranges.
Assuntos
Atletas , Barorreflexo/fisiologia , Resistência Física/fisiologia , Adulto , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , EsportesRESUMO
After cervical spinal cord injury (SCI), orthostatic hypotension and intolerance commonly ensue. The cardiovagal baroreflex plays an important role in the acute regulation of blood pressure (BP) and is associated with the onset of presyncope. The cardiovagal baroreflex is dysfunctional after SCI; however, this may be influenced by either increased stiffening of the arteries containing the stretch-receptors (which has been shown in SCI) or a more downstream neural mechanism (i.e., solitary nucleus, sinoatrial node). Identifying where along this pathway baroreflex dysfunction occurs may highlight a potential therapeutic target. This study examined the relationship between spontaneous cardiovagal baroreflex sensitivity (BRS) and common carotid artery (CCA) stiffness in those with high level SCI before and after midodrine (alpha1-agonist) administration, as well as in able-bodied controls, to evaluate: (1) the role arterial stiffening plays mediating baroreflex function after SCI and (2) the effect of normalizing BP on these parameters. Three to five min recordings of beat-by-beat BP and heart rate, as well as 30 sec duration recordings of CCA diameter were used for analysis. All participants were tested supine and during upright-tilt. Arterial stiffness (ß-stiffness index) was elevated in those with SCI when upright (+12%; p<0.05). Further, ß-stiffness index was negatively related to reduced BRS in those with SCI when upright (R2=0.55; p<0.05), but not in able-bodied persons. Normalizing BP did not improve BRS or CCA stiffness. This study clearly shows that reduced BRS is closely related to increased arterial stiffness in the population with SCI.
Assuntos
Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Barorreflexo/fisiologia , Midodrina/farmacologia , Traumatismos da Medula Espinal/complicações , Rigidez Vascular/fisiologia , Adolescente , Agonistas de Receptores Adrenérgicos alfa 1/administração & dosagem , Adulto , Barorreflexo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Artéria Carótida Primitiva/efeitos dos fármacos , Artéria Carótida Primitiva/fisiopatologia , Medula Cervical/lesões , Feminino , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Midodrina/administração & dosagem , Postura/fisiologia , Resultado do Tratamento , Rigidez Vascular/efeitos dos fármacos , Adulto JovemRESUMO
High-intensity exercise induces marked physiological stress affecting the secretion of catecholamines. Sustained elevations in catecholamines are thought to desensitize cardiac beta receptors and may be a possible mechanism in impaired cardiac function following strenuous exercise. In addition, attenuated arterial-ventricular coupling may identify vascular mechanisms in connection with postexercise attenuations in ventricular function. Thirty-nine normally active (NA) and endurance-trained (ET) men and women completed an echocardiographic evaluation of left ventricular function before and after an acute bout of high-intensity interval exercise (15 bouts of 1:2 min work:recovery cycling: 100% peak power output and 50 W, respectively). Following exercise, time to peak twist and peak untwisting velocity were delayed (P < 0.01) but did not differ by sex or training status. Interactions for sex and condition (rest vs. exercise) were found for longitudinal diastolic strain rate (men, 1.46 ± 0.19 to 1.28 ± 0.23 s(-1) vs. women, 1.62 ± 0.25 to 1.63 ± 0.26 s(-1); P = 0.01) and arterial elastance (men 2.20 ± 0.65 to 3.24 ± 1.02 mmHg · ml(-1) · m(-2) vs. women 2.51 ± 0.61 to 2.93 ± 0.68 mmHg · ml(-1) · m(-2); P = 0.04). No cardiac variables were found associated with catecholamine levels. The change in twist mechanics was associated with baseline aortic pulse-wave velocity (r(2) = 0.27, P = 0.001). We conclude that males display greater reductions in contractility in response to high-intensity interval exercise, independent of catecholamine concentrations. Furthermore, a novel association of arterial stiffness and twist mechanics following high-intensity acute exercise illustrates the influence of vascular integrity on cardiac mechanics.