An overall view of physical exercise prescription and training monitoring for heart failure patients

Physical training for chronic heart failure (CHF) patients is well known in the scientific realm, although there are many different methods of physical exercise prescribed and different ways of monitoring such training. The object of this review is to discuss prescription and monitoring methods of physical exercise for CHF patients. (Cardiol J 2010; 17, 6: 644-649

Reproducibility of the Self-Controlled Six-Minute Walking Test in Heart Failure Patients

INTRODUCTION: The six-minute walk test (6WT) has been proposed to be a submaximal test, but could actually demand a high level of exercise intensity from the patient, expressed by a respiratory quotient >1.0, following the guideline recommendations. Standardizing the 6WT using the Borg scale was proposed to make sure that all patients undergo a submaximal walking test. PURPOSE: To test the reproducibility of the six-minute treadmill cardiopulmonary walk test (6CWT) using the Borg scale and to make sure that all patients undergo a submaximal test. METHODS: Twenty-three male heart failure patients (50&plusmn;9 years) were included; these patients had both ischemic (5) and non-ischemic (18) heart failure with a left ventricle ejection fraction of 23&plusmn;7%, were diagnosed as functional class NYHA II-III and were undergoing optimized drug therapy. Patients were guided to walk at a pace between "relatively easy and slightly tiring" (11 and 13 on Borg scale). The 6CWT using the Borg scale was performed two times on a treadmill with zero inclination and patient control of speed with an interval of 24 hours. During the sixth minute, we analyzed ventilation (VE, L/min), respiratory quotient, Oxygen consumption (VO2, ml/kg/min), VE/VCO2 slope, heart rate (HR, bpm), systolic blood pressure (SBP, mmHg), diastolic (DBP, mmHg) blood pressure and distance. RESULTS: The intraclass correlation coefficients at the sixth minute were: HR (r i=0.96, p<0.0001), VE (r i=0.84, p<0.0001), SBP (r i=0.72, p=0.001), distance (r i=0.88, p<0.0001), VO2 (r i=0.92, p<0.0001), SlopeVE/VCO2 (r i=0.86, p<0.0001) and RQ<1 (r i=0.6, p=0.004). CONCLUSION: Using the 6CWT with the Borg scale was reproducible, and it seems to be an appropriate method to evaluate the functional capacity of heart failure patients while making sure that they undergo a submaximal walking test

The Relationship Between Heart Rate Reserve and Oxygen Uptake Reserve in Heart Failure Patients on Optimized and Non-Optimized Beta-Blocker Therapy

BACKGROUND: The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients either on non-optimized or off beta-blocker therapy is known to be unreliable. The aim of this study was to evaluate the relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in heart failure patients receiving optimized and non-optimized beta-blocker treatment during a treadmill cardiopulmonary exercise test. METHODS: A total of 27 sedentary heart failure patients (86% male, 50±12 years) on optimized beta-blocker therapy with a left ventricle ejection fraction of 33±8% and 35 sedentary non-optimized heart failure patients (75% male, 47±10 years) with a left ventricle ejection fraction of 30±10% underwent the treadmill cardiopulmonary exercise test (Naughton protocol). Resting and peak effort values of both the percentage of oxygen consumption reserve and percentage of heart rate reserve were, by definition, 0 and 100, respectively. RESULTS: The heart rate slope for the non-optimized group was derived from the points 0.949±0.088 (0 intercept) and 1.055±0.128 (1 intercept), p<0.0001. The heart rate slope for the optimized group was derived from the points 1.026±0.108 (0 intercept) and 1.012±0.108 (1 intercept), p=0.47. Regression linear plots for the heart rate slope for each patient in the non-optimized and optimized groups revealed a slope of 0.986 (almost perfect) for the optimized group, but the regression analysis for the non-optimized group was 0.030 (far from perfect, which occurs at 1). CONCLUSION: The relationship between the percentage of oxygen consumption reserve and percentage of heart rate reserve in patients on optimized beta-blocker therapy was reliable, but this relationship was unreliable in non-optimized heart failure patients

Habitat amount and ambient temperature dictate patterns of anuran diversity along a subtropical elevational gradient

Aim: Patterns of diversity along elevational gradients are driven by species characteristics but remain poorly understood. Filling this gap is imperative given the deteriorating conservation status of anurans worldwide. Here, we examine frog diversity and species composition along a sharp subtropical elevational gradient and assess the degree to which these are determined by environmental and spatial predictors. Location: An extensive southern Brazilian Atlantic Forest elevational gradient ranging from 300 to 1,800 m above sea level. Methods: We sampled 38 ponds and used structural equation modelling to examine the direct and indirect effects of area, climate, habitat amount, habitat complexity and productivity on frog species richness and abundance. We also applied joint species distribution models to investigate the importance of these predictors on frog species composition using species distribution and co-occurrence along the elevational gradient. Results: We recorded 12,636 individuals of 41 frog species. Frog species richness was highest at intermediate elevations, showing a hump-shaped pattern. Frog abundance was highest at lowlands and decreased towards higher elevations. We found support for only the habitat amount hypothesis in explaining overall species richness. Although temperature had a positive influence on productivity and frog abundance, neither predictors were related to species richness. Species composition diverged markedly between lowland and highland frog assemblages, which was mainly attributed to differences in ambient temperature. Main conclusion: Elevations containing more extensive natural habitat areas retained the most species-rich frog assemblages. The mid-elevational peak is likely attributed to lowland habitat (1,400 masl). The entire elevational gradient is, however, critical in maintaining anuran species diversity as lowland assemblages are distinct from those at mid- to high elevations. Our study also shows that anthropogenic habitat loss has a decisive effect on montane frog diversity, reinforcing the need to effectively protect these areas

Requisitos básicos para implementação de um sistema de procedimentos computadorizados no Laboratório de Interfaces Homem-Sistema - LABIHS

O Laboratório de Interfaces Homem-Sistema (LABIHS) é formado por um conjunto de equipamentos e programas de computadores que simulam os processos de uma usina nuclear com 930 MWe de potência, formando um simulador compacto de uma planta nuclear PWR (Pressurized Water Reactor) e constituindo uma sala de controle avançada com várias interfaces gráficas representando os vários sistemas que compõem o reator nuclear. Uma das linhas de pesquisa do LABIHS é o desenvolvimento e avaliação de sistemas de procedimentos computadorizados (PBCs) para salas de controle avançadas de plantas industriais. Este relatório tem como principal objetivo descrever os requisitos básicos para implementação do Cliente PBC a ser implementado para a planta nuclear do simulador do LABIHS bem como descrever o estágio atual de implementação deste sistema no laboratório

Exercise capacity in early and late adult heart transplant recipients

Background: The aim of this study was to compare peak oxygen consumption (VO2), heartrate (HR) reserve and HR recovery in early and late heart transplant recipients. Moreover, wealso aimed to correlate peak VO2 and HR reserve.Methods: Fivteen heart transplant recipients (8 early and 7 late), 8 ± 3 and 161 ± 58 monthsafter transplantation, respectively, performed a cardiopulmonary exercise test.Results: Early heart transplant recipients showed lower HR reserve compared to late heart transplantrecipients, 39 ± 15 vs. 58 ± 19 bpm (p = 0.049), respectively. Peak VO2 (23.4 ± 4 vs. 21.8 ± 5 mL/kg/min, p = 0.56), VO2 respiratory compensation point (18.7 ± 2 vs. 18.5 ± 4 mL//kg/min, p = 0.48) and time of exercise testing (14 ± 3 vs. 13 ± 3 min, p = 0.95) %age--predicted peakVO2 (65 ± 12 vs. 70 ± 10%, p = 0.24) were not different between the groups.Moreover, peak VO2 and %age-predicted peakVO2 correlated with HR reserve only in early hearttransplant recipients (r = 0.89, p = 0.003 and r = 0.71, p = 0.04, respectively). Early hearttransplant recipients increased HR (2.5 ± 2.0% at fi rst minute and 0.7 ± 2.3% at the secondminute), while late recipients decreased HR (–6.0 ± 4.7 at fi rst minute and –15.5 ± 2.4 at thesecond minute) at the recovery period of cardiopulmonary exercise test.Conclusions: Exercise capacity did not show difference between early and late heart transplantrecipients. HR reserve was higher in late compared to early recipients. HR reserve onlycorrelated with peak VO2 in early recipients. Moreover, only late heart transplant recipientsshowed decrease in HR during the recovery period of cardiopulmonary exercise test

A systematic review of the effects of different types of therapeutic exercise on physiologic and functional measurements in patients with HIV/AIDS

Several studies have reported the benefits of exercise training for adults with HIV, although there is no consensus regarding the most efficient modalities. The aim of this study was to determine the effects of different types of exercise on physiologic and functional measurements in patients with HIV using a systematic strategy for searching randomized controlled trials. The sources used in this review were the Cochrane Library, EMBASE, MEDLINE, and PEDro from 1950 to August 2012. We selected randomized controlled trials examining the effects of exercise on body composition, muscle strength, aerobic capacity, and/or quality of life in adults with HIV. Two independent reviewers screened the abstracts using the Cochrane Collaboration's protocol. The PEDro score was used to evaluate methodological quality. In total, 29 studies fulfilled the inclusion criteria. Individual studies suggested that exercise training contributed to improvement of physiologic and functional parameters, but that the gains were specific to the type of exercise performed. Resistance exercise training improved outcomes related to body composition and muscle strength, with little impact on quality of life. Aerobic exercise training improved body composition and aerobic capacity. Concurrent training produced significant gains in all outcomes evaluated, although moderate intensity and a long duration were necessary. We concluded that exercise training was shown to be a safe and beneficial intervention in the treatment of patients with HIV

Physical activity profile in heart failure patients from a Brazilian tertiary cardiology hospital

Background: Physical activity (PA) has proven benefits in the primary prevention of heart diseases such as heart failure (HF). Although it is well known, HF PA habits and physicians&#8217; advice have been poorly described. The aim of this study was to investigate if physicians were advising HF patients to exercise and to quantify patients&#8217; exercise profiles in a complex cardiology hospital. Methods: All 131 HF patients (80 male, average age 53 &#177; 10 years, NYHA class I&#8211;V, left ventricular ejection fraction 35 &#177; 11%, 35 ischemic, 35 idiopatic, 32 hypertensive and 29 with Chagas disease) went to the hospital for a HF routine check-up. On this occasion, after seeing the physician , we asked the patients if the physician had advised them about PA. Then, we asked them to fill in the international physical activity questionnaire (IPQA) Short Form to classify their PA level. Results: Our data showed a significant difference between patients who had received any kind of PA advice from physicians (36%) and those who had not (64%,

Norepinephrine Remains Increased in the Six-Minute Walking Test after Heart Transplantation

OBJECTIVE: We sought to evaluate the neurohormonal activity in heart transplant recipients and compare it with that in heart failure patients and healthy subjects during rest and just after a 6-minute walking test. INTRODUCTION: Despite the improvements in quality of life and survival provided by heart transplantation, the neurohormonal profile is poorly described. METHODS: Twenty heart transplantation (18 men, 49±11 years and 8.5±3.3 years after transplantation), 11 heart failure (8 men, 43±10 years), and 7 healthy subjects (5 men 39±8 years) were included in this study. Blood samples were collected immediately before and during the last minute of the exercise. RESULTS: During rest, patients' norepinephrine plasma level (659±225 pg/mL) was higher in heart transplant recipients (463±167 pg/mL) and heathy subjects (512±132), p<0.05. Heart transplant recipient's norepinephrine plasma level was not different than that of healthy subjects. Just after the 6-minute walking test, the heart transplant recipient's norepinephrine plasma level (1248±692 pg/mL) was not different from that of heart failure patients (1174±653 pg/mL). Both these groups had a higher level than healthy subjects had (545±95 pg/mL), p<0.05. CONCLUSION: Neurohormonal activity remains increased after the 6-minute walking test after heart transplantation