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BACKGROUND: Left ventricular (LV) assist devices (LVADs) can prolong survival and improve quality of life in end-stage heart failure. AIMS: Review outcomes of the Western Australian LVAD programme. METHODS: Retrospective database and medical record review. RESULTS: One hundred forty-seven LVADs have been implanted in 23 years, of which 95 were newer-generation devices (HeartWare HVAD [HW], HeartMate II and HeartMate 3). Presented data refer to these devices only. Most patients (94%) were classed as bridge-to-transplant or -candidacy/decision, with the remainder classed as 'destination therapy' (DT). Mean LV ejection fraction was 20%, and 36% had severe right ventricular dysfunction. Sixty-two percent of patients had a nonischaemic cardiomyopathy. Following LVAD implant, the median length of stay in intensive care was 2 days, and in the hospital overall was 23 days. Ninety-six percent of patients survived to hospital discharge, and, following discharge, 98% of days with LVAD were spent as an outpatient. The median number of hospital readmissions was 1.5 per patient per year. LVAD-associated infection requiring admission or intravenous antibiotics at any time after implant occurred in 36%, significant gastrointestinal bleeding in 19% and stroke in 11%. The percentage of patients alive with LVAD still in situ at 1, 2 and 5 years was 94%, 88% and 62% respectively, which exceeds current international registry outcomes. All DT patients survived at least 4 years, spending 97% of days with LVAD as an outpatient. The two longest-surviving HW DT patients worldwide (11.3 and 10.5 years) are among this cohort. CONCLUSIONS: Excellent outcomes can be achieved with LVADs in appropriately selected patients.
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Insuficiencia Cardíaca , Trasplante de Corazón , Corazón Auxiliar , Humanos , Estudios Retrospectivos , Calidad de Vida , Australia , Insuficiencia Cardíaca/terapia , Resultado del TratamientoRESUMEN
INTRODUCTION: General practitioners (GPs) routinely provide care for patients with heart failure (HF); however, adherence to management guidelines, including titrating medication to optimal dose, can be challenging in this setting. This study will evaluate the effectiveness of a multifaceted intervention to support adherence to HF management guidelines in primary care. METHODS AND ANALYSIS: We will undertake a multicentre, parallel-group, randomised controlled trial of 200 participants with HF with reduced ejection fraction. Participants will be recruited during a hospital admission due to HF. Following hospital discharge, the intervention group will have follow-up with their GP scheduled at 1 week, 4 weeks and 3 months with the provision of a medication titration plan approved by a specialist HF cardiologist. The control group will receive usual care. The primary endpoint, assessed at 6 months, will be the difference between groups in the proportion of participants being prescribed five guideline-recommended treatments; (1) ACE inhibitor/angiotensin receptor blocker/angiotensin receptor neprilysin inhibitor at least 50% of target dose, (2) beta-blocker at least 50% of target dose, (3) mineralocorticoid receptor antagonist at any dose, (4) anticoagulation for patients diagnosed with atrial fibrillation, (5) referral to cardiac rehabilitation. Secondary outcomes will include functional capacity (6-minute walk test); quality of life (Kansas City Cardiomyopathy Questionnaire); depressive symptoms (Patient Health Questionnaire-2); self-care behaviour (Self-Care of Heart Failure Index). Resource utilisation will also be assessed. ETHICS AND DISSEMINATION: Ethical approval was granted by the South Metropolitan Health Service Ethics Committee (RGS3531), with reciprocal approval at Curtin University (HRE2020-0322). Results will be disseminated via peer-reviewed publications and conferences. TRIAL REGISTRATION NUMBER: ACTRN12620001069943.
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Rehabilitación Cardiaca , Insuficiencia Cardíaca , Humanos , Calidad de Vida , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/tratamiento farmacológico , Autocuidado/métodos , Atención Primaria de Salud , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Multicéntricos como AsuntoRESUMEN
OBJECTIVES: Coronary artery calcium (CAC) scores derived from computed tomography (CT) scans are used for cardiovascular risk stratification. Artificial intelligence (AI) can assist in CAC quantification and potentially reduce the time required for human analysis. This study aimed to develop and evaluate a fully automated model that identifies and quantifies CAC. METHODS: Fully convolutional neural networks for automated CAC scoring were developed and trained on 2439 cardiac CT scans and validated using 771 scans. The model was tested on an independent set of 1849 cardiac CT scans. Agatston CAC scores were further categorised into five risk categories (0, 1-10, 11-100, 101-400, and > 400). Automated scores were compared to the manual reference standard (level 3 expert readers). RESULTS: Of 1849 scans used for model testing (mean age 55.7 ± 10.5 years, 49% males), the automated model detected the presence of CAC in 867 (47%) scans compared with 815 (44%) by human readers (p = 0.09). CAC scores from the model correlated very strongly with the manual score (Spearman's r = 0.90, 95% confidence interval [CI] 0.89-0.91, p < 0.001 and intraclass correlation coefficient = 0.98, 95% CI 0.98-0.99, p < 0.001). The model classified 1646 (89%) into the same risk category as human observers. The Bland-Altman analysis demonstrated little difference (1.69, 95% limits of agreement: -41.22, 44.60) and there was almost excellent agreement (Cohen's κ = 0.90, 95% CI 0.88-0.91, p < 0.001). Model analysis time was 13.1 ± 3.2 s/scan. CONCLUSIONS: This artificial intelligence-based fully automated CAC scoring model shows high accuracy and low analysis times. Its potential to optimise clinical workflow efficiency and patient outcomes requires evaluation. KEY POINTS: ⢠Coronary artery calcium (CAC) scores are traditionally assessed using cardiac computed tomography and require manual input by human operators to identify calcified lesions. ⢠A novel artificial intelligence (AI)-based model for fully automated CAC scoring was developed and tested on an independent dataset of computed tomography scans, showing very high levels of correlation and agreement with manual measurements as a reference standard. ⢠AI has the potential to assist in the identification and quantification of CAC, thereby reducing the time required for human analysis.
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Enfermedad de la Arteria Coronaria , Vasos Coronarios , Masculino , Humanos , Persona de Mediana Edad , Anciano , Femenino , Vasos Coronarios/diagnóstico por imagen , Inteligencia Artificial , Calcio , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Angiografía Coronaria/métodosRESUMEN
PURPOSE: Changes in left ventricular mass (LVM) and end-diastolic volume (EDV) in response to exercise training are important determinants of functional capacity in health and disease, but the impact of different exercise modalities remains unclear. METHODS: Using a randomized crossover design we studied the impact of resistance (RES) and endurance (END) training using cardiac magnetic resonance imaging in previously untrained monozygotic (MZ) and dizygotic (DZ) twin pairs (n = 72; 22 MZ pairs, 14 DZ same-sex pairs; 26.1 ± 5.4 yr). Twins, as pairs, undertook 3 months of RES and 3 months of END training (order randomized), separated by a 3-month washout. RESULTS: Group results revealed that END increased LVM (P < 0.001) and EDV (P = 0.007), whereas RES did not (P > 0.05). A higher proportion of individuals responded to END than RES for LVM (72% vs 38%, P < 0.001) and EDV (67% vs 40%, P = 0.003). Baseline cross-sectional intraclass correlations were higher for MZ than DZ twin pairs for all variables (e.g., LVM heritability = 0.42), but no significant correlations were apparent between pairs for change in any variable in response to either RES or END (P > 0.05). CONCLUSIONS: Our findings indicate that cardiac adaptation in response to exercise is modality-specific and that low responders to one mode of exercise can be high responders to an alternative. Heritability estimates based on cross-sectional data, which suggested a genetic contribution to LVM, do not accord with estimates based on training effects, which indicated limited genetic impact on adaptation in this 3-month study of exercise training. This study has implications for understanding the physiological and health impacts of typically used exercise modalities on cardiac adaptation in previously untrained individuals.
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Gemelos Dicigóticos , Gemelos Monocigóticos , Estudios Transversales , Ejercicio Físico , Terapia por Ejercicio , Humanos , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Gemelos Dicigóticos/genética , Gemelos Monocigóticos/genéticaRESUMEN
PURPOSE: No previous study has described sex differences in chronic cardiac adaptation in response to distinct modalities of exercise training in humans. METHODS: Cardiac magnetic resonance imaging (1.5 T) was used to assess left ventricular (LV) outcomes in 78 untrained subjects (46F, 26 M; 26.1 ± 5.4 yr). Subjects underwent 3 months of closely supervised and monitored resistance (RES) and endurance (END) training, separated by a 3-month washout period. RESULTS: LV mass (LVM) increased in response to END in both sexes (females â³3.98 ± 7.98 g, P = 0.002; males â³5.99 ± 10.67 g, P = 0.005), whereas LV end-diastolic volume (EDV) increased in males (â³7.48 ± 11.91 mL, P = 0.002) but not females (â³1.54 ± 10.49 mL, P = 0.373). In response to RES, LVM and EDV did not increase in either sex. The proportion of subjects exhibiting a positive response to training (i.e., a change >0) for LVM and EDV did not differ between sexes for either training modality. CONCLUSION: Eccentric hypertrophy in response to END training was more apparent in males than females, whereas there were no notable cardiac changes between sexes for RES training. The proportion of low versus high responders to training was not sex specific for LVM or EDV in response to either commonly prescribed exercise training modality.
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Entrenamiento Aeróbico/métodos , Hipertrofia Ventricular Izquierda/etiología , Entrenamiento de Fuerza/métodos , Adulto , Estudios Cruzados , Estudios Transversales , Ejercicio Físico , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Hipertrofia Ventricular Izquierda/fisiopatología , Imagen por Resonancia Magnética , Masculino , Factores SexualesRESUMEN
As men age, serum testosterone (T) concentrations decrease, as do fitness, strength, and lean mass. Whether testosterone treatment confers additive benefit to reverse these changes when combined with exercise training in middle-to-older aged men remains unclear. We assessed the effects of T treatment and exercise, alone and in combination, on aerobic capacity (VÌo2peak), body composition, and muscular strength in men 50-70 yr, waist circumference ≥95 cm and low-normal serum T (6-14 nmol·L-1). Participants (n = 80) were randomized to AndroForte5 (testosterone 5.0% wt/vol, 100 mg/2 mL) cream (T), or matching placebo (P), applied transdermally daily, and supervised center-based exercise (Ex) or no additional exercise (NEx), for 12-wk. Exercise increased VÌo2peak and strength versus nonexercise (VÌo2peak: T + Ex: +2.5 mL·kg-1·min-1, P + Ex: +3.2 mL·kg-1·min-1, P < 0.001; leg press: T + Ex: +31 kg, P + Ex: +24 kg, P = 0.006). T treatment did not affect VÌo2peak or strength. Exercise decreased total (T + Ex: -1.7, P + Ex: -2.3 kg, P < 0.001) and visceral fat (T + Ex: -0.1 kg, P + Ex: -0.3 kg, P = 0.003), and increased total (T + Ex: +1.4 kg, P + Ex: +0.7 kg, P = 0.008) and arm lean mass (T + Ex: +0.5 kg, P + Ex: +0.3 kg, P = 0.024). T treatment did not affect total or visceral fat, but increased total (T + Ex: +1.4 kg, T + NEx: +0.7 kg, P = 0.015), leg (T + Ex: +0.3 kg, T + NEx: +0.2 kg, P = 0.024), and arm lean mass (T + Ex: +0.5 kg, T + NEx: +0.2 kg, P = 0.046). T + Ex increased arm lean mass (T + Ex: +0.5 kg vs. P + NEx: -0.0 kg, P = 0.001) and leg strength (T + Ex: +31 kg vs. P + NEx: +12 kg, P = 0.032) compared with P + NEx, with no other additive effects. Exercise training was more effective than T treatment in increasing aerobic capacity and decreasing total and visceral fat mass. T treatment at therapeutic doses increased lean mass but conferred limited additional benefit when combined with exercise. Exercise should be evaluated as an antiaging intervention in preference to testosterone treatment in men.NEW & NOTEWORTHY We illustrate that exercise training generates superior outcomes to testosterone treatment for improving aerobic fitness, muscular strength, and total and visceral fat mass in men 50-70 yr with low-normal serum testosterone concentrations. Adding testosterone treatment to exercise did not provide any additive benefit for these variables. Testosterone treatment alone and exercise alone had similar impacts on lean mass. Therefore, men unable to exercise may obtain benefit from testosterone treatment alone to improve lean mass.
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Composición Corporal/fisiología , Ejercicio Físico/fisiología , Fuerza Muscular/fisiología , Aptitud Física/fisiología , Testosterona/sangre , Anciano , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failure. To date, studies evaluating the impact of aerobic training in patients with LVADs have focused on moderate-intensity exercise. METHODS: This pilot randomized controlled trial compared the effects of high-intensity interval training (HIIT) with those of moderate-intensity continuous training (MICT) on peak oxygen consumption (VÌO2 peak) in patients with LVADs. Secondary outcomes included 6-minute walk test distance, flow-mediated dilation, and anthropometry. Assessments were conducted at baseline and after 12 weeks of supervised training performed 3 times weekly. Participants were randomized to HIIT (4 sets of 4 minutes at 80%-90% VÌO2 reserve, alternating with 3 minutes at 50%-60% VÌO2 reserve) or MICT groups (28 minutes continuously at 50%-60% VÌO2 reserve). Within and between-group differences were analyzed using linear mixed models. Data are expressed as marginal means with 95% confidence intervals or as mean ± SD. RESULTS: A total of 21 participants were randomized (HIIT: age 57.7 ± 13.1 years; nâ¯=â¯11 and MICT: age 55.6 ± 14.2 years; nâ¯=â¯10) (mean ± SD). No major adverse events occurred in response to training in either group. HIIT significantly improved VÌO2 peak (15.6 [13.2-17.8] to 18.4 [16.0-20.8] ml/kg/min) (marginal mean [95% CI]) compared with MICT (16.2 [13.8-18.7] to 17.2 [14.6-19.7] ml/kg/min; p < 0.05 between groups). No significant group differences were detected in secondary outcomes. CONCLUSION: In patients with LVADs, HIIT was well tolerated and increased aerobic capacity more than MICT. These preliminary findings support the prescription of high-intensity exercise in clinically stable patients with LVADs but warrant validation in a larger sample and across a broader range of physiologic and clinical outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.anzctr.org.au, unique identifier: ACTRN12616001596493.
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Terapia por Ejercicio/métodos , Ejercicio Físico/fisiología , Insuficiencia Cardíaca/rehabilitación , Frecuencia Cardíaca/fisiología , Ventrículos Cardíacos/fisiopatología , Entrenamiento de Intervalos de Alta Intensidad/métodos , Función Ventricular Izquierda/fisiología , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/fisiología , Proyectos Piloto , Estudios Prospectivos , Resultado del TratamientoRESUMEN
Up to one-third of COVID-19 patients admitted to intensive care develop an acute cardiomyopathy, which may represent myocarditis or stress cardiomyopathy. Further, while mortality in older patients with COVID-19 appears related to multi-organ failure complicating acute respiratory distress syndrome (ARDS), the cause of death in younger patients may be related to acute heart failure. Cardiac involvement needs to be considered early on in critically ill COVID-19 patients, and even after the acute respiratory phase is passing. This Statement presents a screening algorithm to better identify COVID-19 patients at risk for severe heart failure and circulatory collapse, while balancing the need to protect health care workers and preserve personal protective equipment (PPE). The significance of serum troponin levels and the role of telemetry and targeted transthoracic echocardiography (TTE) in patient investigation and management are addressed, as are fundamental considerations in the management of acute heart failure in COVID-19 patients.
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Cardiología , Infecciones por Coronavirus , Insuficiencia Cardíaca , Control de Infecciones , Miocarditis , Pandemias , Manejo de Atención al Paciente/métodos , Neumonía Viral , Australia/epidemiología , Betacoronavirus , COVID-19 , Cardiología/métodos , Cardiología/organización & administración , Cardiología/tendencias , Consenso , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/prevención & control , Enfermedad Crítica/terapia , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/terapia , Humanos , Control de Infecciones/métodos , Control de Infecciones/organización & administración , Miocarditis/complicaciones , Miocarditis/virología , Nueva Zelanda/epidemiología , Pandemias/prevención & control , Neumonía Viral/epidemiología , Neumonía Viral/prevención & control , Ajuste de Riesgo/métodos , SARS-CoV-2 , Sociedades MédicasRESUMEN
PURPOSE: Left ventricular assist devices (LVAD) are associated with an increased aerobic capacity in patients with chronic heart failure (CHF). However, studies evaluating the impact of LVAD implantation on physical activity (PA) are lacking. The aim of this study was to compare daily PA levels in participants with LVAD with well-matched CHF participants. METHODS: Sixteen participants with an LVAD (age, 59.1 ± 10.8 yr) were case-matched to 16 participants with advanced CHF (age, 58.3 ± 8.7 yr), who were listed or being considered for cardiac transplantation. Participants underwent a cardiopulmonary exercise test to determine peak oxygen consumption (VËO2 peak). Physical activity was monitored continuously for seven consecutive days with an Actiheart monitor. RESULTS: VËO2 peak in the CHF group (12.3 ± 3.5 mL·kg·min) was not significantly different to the LVAD group before LVAD implantation (10.4 ± 2.1 mL·kg·min), but was lower than in the LVAD group after implantation (15.8 ± 4.3 mL·kg·min; P < 0.05). Physical activity was higher in the LVAD (19.7 ± 6.4 kJ·kg·d) compared with the CHF group (11.6 ± 6.9 kJ·kg·d; P = 0.001). The LVAD participants spent more time performing moderate-intensity PA than their CHF counterparts (median, 26 min·d; interquartile range, 24-40 min·d vs median, 12 min·d; interquartile range, 9-16 min·d; P < 0.001). Physical activity was correlated with VËO2 peak (r = 0.582; P = 0.001) across participants in the CHF and LVAD groups. CONCLUSIONS: Higher levels of PA were observed in participants with LVAD compared with patients with advanced CHF. This may be due to a higher VËO2 peak, resulting in an improved capacity to perform activities of daily living with less symptoms.
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Tolerancia al Ejercicio , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Actividades Cotidianas , Anciano , Estudios de Casos y Controles , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/psicología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/fisiología , Calidad de Vida , AutoeficaciaRESUMEN
Cerebral blood flow during exercise is impaired in patients with heart failure implanted with left ventricular assist devices (LVADs). Our aim was to determine whether a 3-mo exercise training program could mitigate cerebrovascular dysfunction. Internal carotid artery (ICA) blood flow and intracranial middle (MCAv) and posterior cerebral (PCAv) artery velocities were measured continuously using Doppler ultrasound, alongside cardiorespiratory measures at rest and in response to an incremental cycle ergometer exercise protocol in 12 LVAD participants (5 female, 53.6 ± 11.8 yr; 84.2 ± 15.7 kg; 1.73 ± 0.08) pre- (PreTR) and post- (PostTR) completion of a 3-mo supervised exercise rehabilitation program. At rest, only PCAv was different PostTR (38.1 ± 10.4 cm/s) compared with PreTR (43.0 ± 10.8 cm/s; P < 0.05). PreTR, the reduction in PCAv observed from rest to exercise (5.2 ± 1.8%) was mitigated PostTR (P < 0.001). Similarly, exercise training enhanced ICA flow during submaximal exercise (~8.6 ± 13.7%), resulting in increased ICA flow PostTR compared with a reduced flow PreTR (P < 0.001). Although both end-tidal partial pressure of carbon dioxide and mean arterial pressure responses during incremental exercise were greater PostTR than PreTR, only the improved PETCO2 was related to the improved ICA flow (R2 = 0.14; P < 0.05). Our findings suggest that short-term exercise training improves cerebrovascular function during exercise in patients with LVADs. This finding should encourage future studies investigating long-term exercise training and cerebral and peripheral vascular adaptation.NEW & NOTEWORTHY Left ventricular assist devices, now used as destination therapy in end-stage heart failure, enable patients to undertake rehabilitative exercise training. We show, for the first time in humans, that training improves cerebrovascular function during exercise in patients with left ventricular assist devices. This finding may have implications for cerebrovascular health in patients with heart failure.
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Circulación Cerebrovascular/fisiología , Terapia por Ejercicio/métodos , Insuficiencia Cardíaca/terapia , Corazón Auxiliar/estadística & datos numéricos , Adaptación Fisiológica , Velocidad del Flujo Sanguíneo , Femenino , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/rehabilitación , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Función Ventricular Izquierda/fisiologíaRESUMEN
BACKGROUND: It is reported that up to 29-52% of patients with cardiac sarcoidosis (CS) may have isolated cardiac sarcoidosis (ICS). The wide variation in prevalence may be related to the diagnostic methods for assessing extracardiac involvement. Whole-body 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) imaging is a useful and increasingly used technique for screening for extracardiac involvement in cases of suspected ICS. This study aims to determine the rate of isolated cardiac involvement with clinically manifest CS using cardiac 18F-FDG PET-CT. METHODS: We performed a retrospective analysis of data in the West Australian Cardiac Sarcoid (WACaS) Database. After cardiologist review and workup, all cases of proven or probable CS, based on either current Heart Rhythm Society criteria for the diagnosis of CS or local expert consensus were included. Only patients who underwent whole body 18F-FDG PET-CT were included in the final analysis. RESULTS: Fifty-two (52) cases of CS were identified. Data on symptoms, imaging findings, treatment and outcomes were collected. Of the 42 patients who underwent diagnostic 18F-FDG PET-CT, 32 demonstrated changes consistent with CS. Of the 32, 69% were male, mean age 50 years at diagnosis. Only 3/32 (9.4%) patients had ICS. Pulmonary involvement occurred in 91% with varied involvement in other organs. The mean number of extracardiac sites at diagnosis was 2.2. CONCLUSIONS: This study demonstrates the utility of 18F-FDG PET-CT in diagnosing extracardiac organ involvement in cases of CS. With the use of this modality, ICS may be rarer than previously reported.
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Cardiomiopatías/diagnóstico por imagen , Bases de Datos Factuales , Fluorodesoxiglucosa F18/administración & dosificación , Tomografía Computarizada por Tomografía de Emisión de Positrones , Sarcoidosis/diagnóstico por imagen , Australia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
INTRODUCTION: In healthy individuals, cerebral blood flow (CBF) increases during exercise, but few studies have compared changes in CBF during exercise in patients with heart failure (HF) to healthy controls (CTRL) or assessed the effects of left ventricular assist devices (LVAD). We hypothesized that subjects implanted with LVAD would exhibit impaired cerebrovascular responses to cycle exercise when compared with age- and sex-matched healthy CTRL subjects but would have enhanced responses relative to subjects with HF. METHODS: Internal carotid artery (ICA) blood flow and intracranial middle (MCAv) and posterior cerebral (PCAv) artery velocities were measured continuously using Doppler ultrasound, alongside cardiorespiratory measures at rest and in response to an incremental submaximal cycle ergometer exercise protocol in nine LVAD participants (58 ± 15 yr, 87 ± 16 kg, 172 ± 8 cm, six females), nine age- and sex-matched subjects with HF (58 ± 8 yr, 84 ± 11 kg, 177 ± 6 cm), and nine CTRL (55 ± 14 yr, 74 ± 16 kg, 168 ± 10 cm). RESULTS: At rest, ICA hemodynamics (velocity, shear rate, and flow) were greater in CTRL and LVAD than that in HF (P < 0.05). Higher MCAv (+5.52 ± 1.59 cm·s, P = 0.003) and PCAv (+5.82 ± 1.41 cm·s, P = 0.001) were also observed in LVAD subjects than healthy CTRL. During exercise, ICA flow increased at all workloads in CTRL, but not in HF or LVAD groups. MCAv increased from baseline in both HF and CTRL participants (P = 0.0001), but not in LVAD subjects. Nonetheless, CTRL and LVAD showed higher MCAv (P = 0.006) and PCAv (P < 0.0001) values throughout exercise than HF. CONCLUSION: Our findings indicate that LVAD subjects exhibit higher CBF at rest and during exercise than matched HF participants but attenuated brain blood flows during exercise when compared with healthy subjects. CBF should be considered when designing exercise training interventions in patients with HF and LVAD.
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Circulación Cerebrovascular/fisiología , Ejercicio Físico/fisiología , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/rehabilitación , Corazón Auxiliar , Adulto , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/fisiología , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Arteria Cerebral Media/diagnóstico por imagen , Arteria Cerebral Media/fisiología , Arteria Cerebral Posterior/diagnóstico por imagen , Arteria Cerebral Posterior/fisiología , Pruebas de Función Respiratoria , Ultrasonografía Doppler DúplexRESUMEN
BACKGROUND: Cardiovascular disease (CVD) is the leading non-malignant cause of death in childhood cancer survivors. Heightened risk of CVD is often attributable to treatment with anthracycline chemotherapy. Anthracycline-mediated cardiac injury may lie latent for years following cessation of treatment and is therefore often not detected until disease is advanced and aggressive therapy is required. Symptomatic CVD may be preceded by subclinical cardiac and vascular dysfunction. This study aimed to determine whether such dysfunction could be detected in healthy, anthracycline-treated survivors of childhood leukaemia. METHODS: Cardiac magnetic resonance imaging (cMRI) with late gadolinium enhancement and endothelial function were used to characterise pre-clinical stages of CVD. Twenty-two long-term (>5 years survival; age 21 ± 3 years) childhood leukaemia survivors were assessed. All survivors were asymptomatic and had normal resting echocardiography. To exclude potential confounding effects of radiotherapy, no survivors had received this treatment. Twenty-two similarly aged (25 ± 3 years) gender-matched controls were recruited for comparison. RESULTS: Left ventricular ejection fraction was lower in the survivors (55.0 ± 4.6%) compared to the controls (59.4 ± 6.2%; p = 0.010). Further, five survivors (23%) had clinically reduced (<50%) left ventricular ejection fraction. Normalised left ventricular end systolic volume was augmented in survivors (40.0 ± 9.1 mL·m2 vs. 34.5 ± 7.5 mL·m2; p = 0.038). Cardiac MRI did not show any late gadolinium enhancement. High resolution, ultrasound-derived flow mediated dilation was impaired in survivors (6.7 ± 2.1% vs. 8.60 ± 1.91%, p = 0.005). CONCLUSIONS: We detected subclinical changes in cardiovascular structure and function indicative of early disease in anthracycline-treated childhood leukaemia survivors with normal echocardiography. Early detection and characterisation of underlying disease allows for timely intervention and improved outcomes in this at-risk population.
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Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF are scant. Eccentric (ECC) cycling is a novel exercise modality that may be particularly suited to patients with CHF, but the acute impacts of ECC cycling on platelet and vascular function are currently unknown. Our null hypothesis was that ECC and concentric (CON) cycling, performed at matched external workloads, would not induce changes in platelet or vascular function in patients with CHF. Eleven patients with heart failure with reduced ejection fraction (HFrEF) took part in discrete bouts of ECC and CON cycling. Before and immediately after exercise, vascular function was assessed by measuring diameter and flow-mediated dilation (FMD) of the brachial artery. Platelet function was measured by the flow cytometric determination of glycoprotein IIb/IIIa activation and granule exocytosis in the presence and absence of platelet agonists. ECC cycling increased baseline artery diameter (pre: 4.0 ± 0.8 mm vs. post: 4.2 ± 0.7 mm; P = 0.04) and decreased FMD%. When changes in baseline artery diameter were accounted for, the decrease in FMD post-ECC cycling was no longer significant. No changes were apparent after CON. Neither ECC nor CON cycling resulted in changes to any platelet-function measures (all P > 0.05). These results suggest that both ECC and CON cycling, at a moderate intensity and short duration, can be performed by patients with HFrEF without detrimental impacts on vascular or platelet function.NEW & NOTEWORTHY This is the first evidence to indicate that eccentric (ECC) cycling can be performed relatively safely by patients with chronic heart failure (CHF), as it did not result in impaired vascular or platelet function compared with conventional cycling. This is important, as acute exercise can transiently increase atherothrombotic risk, and ECC cycling is a novel exercise modality that may be particularly suited to patients with CHF.
Asunto(s)
Plaquetas/fisiología , Insuficiencia Cardíaca/fisiopatología , Ciclismo/fisiología , Plaquetas/metabolismo , Enfermedad Crónica , Ejercicio Físico/fisiología , Terapia por Ejercicio , Femenino , Insuficiencia Cardíaca/metabolismo , Frecuencia Cardíaca/fisiología , Humanos , Persona de Mediana Edad , Esfuerzo Físico/fisiología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismoRESUMEN
PURPOSE: Chronic heart failure (CHF) is characterized by dyspnea and poor exercise tolerance, which decreases aerobic capacity (VËO2peak), a measure strongly correlated with quality of life and mortality. In healthy populations, eccentric (ECC) cycling can be performed at a lower oxygen demand for matched workload, compared with concentric (CON) cycling, but few studies have previously investigated ECC cycling in CHF. We hypothesized that, when matched for external workload (W), an ECC cycling bout would be performed at a lower cardiorespiratory load (VËO2) than CON in patients with CHF. METHODS: Eleven CHF patients (10 males) with impaired left ventricular systolic function (ejection fraction 31% ± 12%) completed a CON VËO2peak test, with the subsequent ECC and CON protocols set at 70% of individual maximal CON power (W). Oxygen consumption (VËO2), RER, minute ventilation (VËE), HR, and rate pressure product were compared between conditions. RESULTS: ECC was performed at a lower VËO2 (12.3 ± 1.3 vs 14.1 ± 0.8 mL·kg·min, P = 0.01), RER (0.92 ± 0.02 vs 0.96 ± 0.01, P = 0.01), and VËE (36.5 ± 4.4 vs 40.2 ± 2.0 L·min, P = 0.04) in comparison with CON, despite both conditions being performed at matched workloads. HR (101 ± 5 vs 96 ± 1 bpm, P = 0.06) and rate pressure product (13,539 ± 788 vs 11,911 ± 227 bpm·mm Hg, P = 0.15) were not significantly different between conditions. CONCLUSION: When matched for external workload, ECC cycling can be performed with a lower oxygen demand than CON in patients with CHF. Eccentric cycling is a promising modality for cardiac rehabilitation in severely deconditioned patients with CHF.
Asunto(s)
Ciclismo/fisiología , Tolerancia al Ejercicio/fisiología , Insuficiencia Cardíaca/fisiopatología , Consumo de Oxígeno , Presión Sanguínea , Enfermedad Crónica , Prueba de Esfuerzo/métodos , Femenino , Insuficiencia Cardíaca/rehabilitación , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Mialgia/etiologíaRESUMEN
Severe burn injury significantly affects cardiovascular function for up to 3 years. However, whether this leads to long-term pathology is unknown. The impact of non-severe burn injury, which accounts for over 80% of admissions in developed countries, has not been investigated. Using a rodent model of non-severe burn injury with subsequent echocardiography we showed significantly increased left ventricular end systolic diameter (LVESD) and ventricular wall thickness at up to 3 months post-injury. Use of propranolol abrogated the changes in cardiac measures observed. Subsequently we investigated changes in a patient cohort with non-severe injury. Echocardiography measured at baseline and at 3 months post-injury showed increased LVESD at 3 months and significantly decreased posterior wall diameter. Finally, 32 years of Western Australian hospital records were used to investigate the incidence of cardiovascular disease admissions after burn injury. People who had experienced a burn had increased hospital admissions and length of stay for cardiovascular diseases when compared to a matched uninjured cohort. This study presents animal, patient and population data that strongly suggest non-severe burn injury has significant effects on cardiovascular function and long-term morbidity in some burn patients. Identification of patients at risk will promote better intervention and outcomes for burn patients.
Asunto(s)
Quemaduras/fisiopatología , Enfermedades Cardiovasculares/fisiopatología , Corazón/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Adulto , Anciano , Animales , Quemaduras/patología , Enfermedades Cardiovasculares/patología , Ecocardiografía , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Puntaje de Gravedad del Traumatismo , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Disfunción Ventricular Izquierda/patología , Adulto JovenRESUMEN
BACKGROUND: Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF). However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL), both in CHF patients and age- and physical activity-matched control participants. METHODS: Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging) with a musculoskeletal model. RESULTS: We found reduced passive SOL forces (â¼30%) (at the same relative levels of muscle stretch) in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized) and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. DISCUSSION: These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening.