Cardiorespiratory Exercise Testing Research Articles

Cardiovascular Drift Response Over Two Different Constant-load Exercises In Healthy Non-athletes. Case Study.

Cardiovascular drift (CV-d) is a steady increase in heart rate (HR) over time while performing constant load moderate intensity exercise (CME) > 20 min. CV-d presents problems for the prescription of exercise intensity by means of HR, because the work rate (WR) during exercise must be adjusted to maintain target HR, thus disturbing the intended effect of the exercise intervention. It has been shown that the increase in HR during CME is due to changes in WR and not to CV-d. PURPOSE: We aimed to investigate whether, indeed, the CV-d in healthy young people exercising at the WR corresponding to the lactate individual anaerobic threshold (IAT) determined in two different cardiorespiratory exercise test (CPT), was related to the WR difference. METHODS: Seven participants (30 ± 3 years old, 1.75 ± 0.1 m., 74.6 ± 12.8 Kg.) performed on different days two CPT with a WR increase of 20 Watts (W) every one or three minutes until exhaustion. The WR corresponding to the IAT was determined during these tests. The participants then performed two CME with a WR corresponding to the IAT. HR and blood lactate (La) were continuously measured during all tests. A comparison between CPTs and CMEs were made using a paired t-test. A one-way ANOVA repeated measurements was used to compare La values during the CME. RESULTS: VO2max (36.9 ± 59 vs. 35.6 ± 5.7 ml·Kg-1·min-1; p > 0.05), maximal HR (181 ± 9 vs. 178 ± 11 bpm; p = 0.3), and peak La (8.7 ± 1.6 vs. 7.8 ± 1.6; p = 0.1) did not differ between CPTs. Maximal power output (271 ± 80 vs. 223 ± 75 W; p < 0.001) and WR at the IAT (164 ± 63 vs. 137 ± 45 W; p > 0.01) were different between CPTs. La between CMEs and minutes 10 and 30 were not different (3 ± 0.4 vs. 3.3 ± 0.5; p = 0.1). One-CME mean HR was 157 ± 12 bpm with an increase of 8 ± 4 bpm between minutes 10-30. Three-MCE HR was 147 ± 14 bpm and the HR increased by 9 ± 7 bpm between minute 10-30. Only a difference in HR between the two CME was found (p = 0.009) whereas there was no difference in the HR change between minute 10-30 (p = 0.7). CONCLUSION: In this case study, the CV-d was not significantly different between the two CMEs (One-IAT and Three-IAT) despite a significant difference in the amount of WR between CMEs (26 ± 19). Other factors aside from the WR like an increase in peripheral blood flow, hyperthermia, plasma volume reduction, catecholamine levels, and training status play a role in the CV-d phenomenon.

Validity of the modified shuttle walk test to assess cardiorespiratory fitness after exercise intervention in overweight/obese adults with primary hypertension

ABSTRACTThe study aimed to assess whether the Modified Shuttle Walk Test (MSWT) can detect changes in cardiorespiratory fitness (CRF) in overweight/obese people with hypertension (HTN) after an exercise intervention evaluating the equation presented in the previous research by Jurio-Iriarte et al. Participants (N= 248) performed a peak cardiorespiratory exercise test (CPET) and MSWT before and after 16-weeks of different types of aerobic exercise intervention. The formula of Jurio-Iriarte et al. was used to predict peak oxygen uptake (V̇O2peak). The correlation between measured and predicted V̇O2peak was strong (r= 0.76, P< 0.001) with a standard error of estimate (SEE) of 4.9 mL·kg−1·min−1; SEE%= 17%. The intraclass correlation coefficient indicates a moderate level of association and agreement (ICC= 0.69; 95% CI 0.34–0.82; P< 0.001) between the measured and predicted V̇O2peak. When analyzing obese participants alone (N= 128), MSWT equation was more accurate compared to the whole sample (ICC= 0.76; 95% CI 0.52–0.87). The relationship between the change of measured and predicted V̇O2peak at follow-up was weak (r= 0.42, P< 0.001) with a 31% SEE, and a low level of association and agreement (ICC= 0.31; 95% CI 0.06–0.49; P< 0.001). In conclusion, although MSWT does not accurately predict CRF in people with HTN after exercise intervention and questions its validity, the new equation may have practical application to estimate V̇O2peak for obese people with HTN when CPET is not available.Abbreviations: AC: Attention Control; BM: Body Mass; BP: Blood Pressure; CI: Confidence Interval; CRF: Cardiorespiratory Fitness; CPET: Cardiopulmonary Exercise Test; HTN: Primary Hypertension; HR: Heart Rate; HV-HIIT: High-Volume and High-Intensity Interval Training; ICC: Intraclass Correlation Coefficient; LV-HIIT: Low-Volume and High-Intensity Interval Training; MICT: Moderate-intensity continuous training; MSWT: Modified Shuttle Walk Test; SD: Standard Deviation; SEE: Standard Error of Estimate; V̇O2peak: Peak Oxygen Uptake.

A Comparison of Two VO2max Treadmill CPETs in Highly Trained Distance Runners

Measuring maximal oxygen consumption (VO2max) via treadmill testing is a popular procedure for testing aerobic power and subsequently developing exercise prescriptions. Previous studies have produced conflicting results when comparing horizontal and incline graded treadmill protocols designed to assess VO2max, and the variability may be due to the heterogeneity of subjects, having different fitness levels and backgrounds. PURPOSE: To prospectively compare the VO2max value attained during a horizontal (increment in speed only) (SOVO2max) and an inclined (constant speed with increment in grade only) (GOVO2max) cardiorespiratory exercise tests (CPETs) in highly trained distance runners. A secondary purpose examined if the ventilatory threshold (VT) determined from the SOVO2max and GOVO2max CPETs occurred at the same percent of VO2max (% VO2max @ VT). METHODS: After a familiarization session performing the Bruce Protocol, VO2max and % VO2max @ VT were evaluated in 16 male distance runners, some who preferred hilly terrain and some who preferred flat or track running, using the SOVOmax and GOVOmax CPETs. Dependent samples t-tests were used to compare the VO2max and % VO2max @ VT results between the SOVO2max and GOVO2max CPETs. RESULTS: VO2max values were significantly higher from the GOVO2max in comparison to the SOVO2max protocol (76.1 and 71.2 mLO2/kg/min, p=. 005); however, the % VO2max @ VT was not significantly different between the GOVO2max and SOVO2max protocols (77.5% and 77.2%, p=.825). CONCLUSION: Higher VO2max values were attained on the GOVO2max CPET, even on those who reported they were track athletes and favored running on the flat surfaces. These results agree with previous research that found athletes who train and compete on an exclusively flat surface or hilly terrain both tend to produce higher VO2max values on CPETs that include changes in treadmill grade. However, due to the non-significant difference in % VO2max @ VT observed between the SOVO2max or GOVO2max CPETs, for the determination of training thresholds, runner specialty (flat versus hill runners) should therefore be considered when selecting the most appropriate CPET in this athletic population.

Exercise testing in heart failure: a contemporary discussion in an era of novel diagnostic techniques and biomarkers.

The purpose of this review is to highlight recent advances in the field of exercise testing for patients with heart failure. The importance of assessment of cardiorespiratory fitness (CRF) and exercise testing in heart failure is highlighted in the consensus recommendation of the American Heart Association. Contemporary studies have validated the independent and incremental strength of CRF metrics in patients with heart failure and coronary artery disease. The use of respiratory gas analysis and imaging or hemodynamics during physical exercise is feasible and results in high prognostic utility across the continuum of heart failure. Understanding how CRF metrics complement existing and novel biomarkers and risk scores is an emerging subject of scientific inquiry. In the current era of personalized medicine, integrating CRF, imaging and circulating biomarkers will allow us to further develop individualized strategies for improving outcome in patients with heart failure.

Cardiorespiratory Coordination in Repeated Maximal Exercise.

Increases in cardiorespiratory coordination (CRC) after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC) analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate) was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1) were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax), maximal oxygen consumption (VO2 max), or ventilatory threshold (VT), an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08) was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43) in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT) between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC evaluation in the assessment and interpretation of cardiorespiratory exercise testing.

Assessment of dyspnea and dynamic hyperinflation in male patients with chronic obstructive pulmonary disease during a six minute walk test and an incremental treadmill cardiorespiratory exercise test

The six minute walk test (6MWT) is a standardized test that provides information on exercise capacity in patients with COPD. It is considered a submaximal test in opposition to incremental cardiopulmonary exercise tests (CPET) that provide valuable information on all the systems involved in exercise. Objectives1. To compare the perceptive, physiological responses and degree of dynamic hyperinflation during two exercise tests: the 6MWT and the incremental CPET on a treadmill. 2. To evaluate how dyspnea is related to dynamic hyperinflation (DH) and other functional parameters in both tests. Methods29 stable COPD male patients, age 68±5.8 years, mean post-bronchodilator FEV1 57±11%, were recruited. To evaluate dynamic hyperinflation, inspiratory capacity (IC) was measured at rest and upon completing each one of the tests. At the same time, perceived dyspnea and leg discomfort were rated on specific modified Borg scales. ResultsThe mean walk distance in 6MWT was 494±88m. The Borg scale rating for shortness of breath upon completing the test was 4.7±2, whilst 2.9±2 for leg discomfort. IC changed from 2.53±0.63l before to 2.34±0.60l after completion of the test.In the treadmill CPET, maximal oxygen consumption (V˙O2 max) was 21.8±5mL/kg/min with 6.6±2 dyspnea and 4.3±2 leg discomfort on Borg scales. IC changed from 2.17±0.53l to 1.20±0.43l. ConclusionsDynamic hyperinflation occurs in male COPD patients during submaximal exercise such as the 6MWT. This phenomenon is more pronounced after incremental CPET on a treadmill. Despite being dyspnea the dominant limiting symptom for both tests, we observed different physiological responses.

Has the ideal and universal prognostic index in cardiorespiratory exercise testing been identified?

Has the ideal and universal prognostic index in cardiorespiratory exercise testing been identified?

Association between Modified Shuttle Walk Test and cardiorespiratory fitness in overweight/obese adults with primary hypertension: EXERDIET-HTA study

The aims of the study were to evaluate the relationship between Modified Shuttle Walk Test (MSWT) with peak oxygen uptake (V˙O2peak) in overweight/obese people with primary hypertension (HTN) and to develop an equation for the MSWT to predict V˙O2peak. Participants (N = 256, 53.9 ± 8.1 years old) with HTN and overweight/obesity performed a cardiorespiratory exercise test to peak exertion on an upright bicycle ergometer using an incremental ramp protocol and the 15-level MSWT. The formula of Singh et al was used as a template to predict V˙O2peak, and a new equation was generated from the measured V˙O2peak-MSWT relationship in this investigation.The correlation between measured and predicted V˙O2peak for Singh et al equation was moderate (r = 0.60, P < .001) with a standard error of the estimate (SEE) of 4.92 mL·kg−1 minute−1, SEE% = 21%. The correlation between MSWT and measured V˙O2peak as well as for the new equation was strong (r = 0.72, P < .001) with a SEE of 4.35 mL·kg−1 minute−1, SEE% = 19%. These results indicate that MSWT does not accurately predict functional capacity in overweight/obese people with HTN and questions the validity of using this test to evaluate exercise intolerance. A more accurate determination from a new equation in the current study incorporating more variables from MSWT to estimate V˙O2peak has been performed but still results in substantial error.

Diet optimization in patients with obesity and diastolic heart failure based on the assessment of indicators of metabolism during physical exertion

The objective of the work was to examine the performance of basal metabolism and body composition in obese patients with diastolic heart failure (DHF) to identify optimal needs of these patients in the nutrients and energy. We studied 222 patients with obesity, that were divided into four groups depending on the degree of obesity and the presence or absence of DHF with preserved systolic function of the left ventricle (2 groups of obese patients with an initial degree I-II, 2 groups - a pronounced degree of obesity III). Basal metabolism by indirect respiratory calorimetry, physical activity at home and cardiorespiratory exercise testing were evaluated in these groups of patients. It has been shown that patients with obesity and secondary DHF have significantly lower physical activity during the day, resulting in the reduction of the overall length of the active time of day to 18.5-26.9%, and in the decrease of the proportion of time performing heavy and moderate work to 27.6-80.3%. Anaerobic threshold in obese patients I-II degree was 62.9% of maximum oxygen consumption (VO2pik) (rate is more than 60%), in patients with obesity III degree - 77.6% of VO2pik. Alveolar gas exchange also was not broken - the CO2 ventilation equivalent was equal respectively 23.4±2.8 and 28.9±1.5 (rate is less than 32). Thus, cardiopulmonary exercise testing have demonstrated that cardiopulmonary causes of dyspnea in obese patients without DHF were absent; and the reason for the decrease of exercise tolerance in patients with obesity III degree was the detraining. The reason for inactivity in patients with obesity and DHF was a marked reduction in exercise capacity due to violations of alveolar ventilation and reducing aerobic capacity of muscles. It was found that accustomed physical activity of patients at home didn't allow patients with obesity and DHF to carry out effective fat oxidation, due to the rapid achievement of the anaerobic threshold. It has been suggested that this effect may be the cause of metabolic progression of obesity in patients with DHF. It was found that patients with obesity and secondary DHF were characterized by a more pronounced oxidation of the protein, compared with similar patients without DHF, which made actual the muscle mass patronage under diet therapy management of patients. The optimum performance of the chemical composition and energy value of the diet have been calculated for patients with obesity of varying severity in conjunction with SDS.

Exercise tolerance in obstructive sleep apnea-hypopnea (OSAH), before and after CPAP treatment: Effects of autonomic dysfunction improvement

BackgroundObstructive sleep apnea hypopnea (OSAH) is associated with decreased exercise tolerance and autonomic abnormalities and represents a risk for cardiovascular diseases. The aim of the study was to evaluate the effects of CPAP on cardiovascular autonomic abnormalities and exercise performance in patients with OSAH without changes in lifestyle and body weight during treatment. MethodsTwelve overweight subjects with OSAH underwent anthropometric measures, autonomic cardiovascular and incremental symptom-limited cardio-respiratory exercise tests before and after two months of treatment with CPAP. ResultsLower frequency component of power spectrum of heart rate variability (59.5±24.2 msec2 vs 43.2±25.9 msec2; p<0.05) and improvements of maximal workload (99.3±13.5 vs 108.3±16.8%pred.; p<0.05) and peak oxygen consumption (95.3±7.6 vs 105.5±7.9%pred.; p<0.05) were observed in these patients after CPAP, being their BMI unchanged. ConclusionsCPAP-induced decrease of sympathetic hyperactivity is associated with better tolerance to the effort in OSAH patients that did not change their BMI and lifestyle, suggesting that OSAH limits per se the exercise capacity.

Is the Veterans Specific Activity Questionnaire Valid to Assess Older Adults Aerobic Fitness?

Aerobic fitness in older adults is related to health status, incident disability, nursing home admission, and all-cause mortality. The most accurate quantification of aerobic fitness, expressed as peak oxygen consumption in mL·kg·min, is the cardiorespiratory exercise test; however, it is not feasible in all settings and might offer risk to patients. The Veterans Specific Activity Questionnaire (VSAQ) is a 13-item self-administered symptom questionnaire that estimates aerobic fitness expressed in metabolic equivalents (METs) and has been validated to cardiovascular patients. The purpose of this study was to assess the validity and reliability of the VSAQ in older adults without specific health conditions. A methodological study with a cross-sectional design was conducted with 28 older adults (66-86 years). The VSAQ was administered on 3 occasions by 2 evaluators. Aerobic capacity in METs as measured by the VSAQ was compared with the METs found in an incremental shuttle walk test (ISWT) performed with a portable metabolic measurement system and with accelerometer data. The validity of the VSAQ was found to be moderate-to-good when compared with the METs and distance measured by the ISWT and with the moderate activity per day and steps per day obtained by accelerometry. The Bland-Altman graph analysis showed no values outside the limits of agreement, suggesting good precision between the METs estimated by questionnaire and the METs measured by the ISWT. Also, the intrarater and interrater reliabilities of the instrument were good. The results showed that the VSAQ is a valuable tool to assess the aerobic fitness of older adults.

Contribution of respiratory gas exchanges assessment in heart failure rehabilitation

The cardiorespiratory exercise test provides valuable information in a rehabilitation program for chronic heart failure. It initially allows objective measurement of the patient's functional capacity by measuring VO 2 and ventilatory threshold. The description of respiratory adaptations gives informations on ventilatory efficiency and the existence of inadequate hyperventilation. This objective description of the performance and exercise tolerance will allow: to select patients to rehabilitate, provide prognostic information, choose retraining protocol best suited to the patient's situation, ensure monitoring by quantifying improved performance and tolerance to exercise and if necessary read just the terms of the retraining program. The contribution of this type of evaluation will be detailed in the different perspectives mentioned using concrete examples. These objective measures achieved in strict conditions allow to assess, select, guide and reassure, encourage patients to optimize their rehabilitation program. The interest of the evaluation of endurance by measuring VO 2 and ventilatory threshold can be demonstrated at various stages of heart failure patients rehabilitation course.

The influence of aerobic fitness status on ventilatory efficiency in patients with coronary artery disease

OBJECTIVE:To test the hypotheses that 1) coronary artery disease patients with lower aerobic fitness exhibit a lower ventilatory efficiency and 2) coronary artery disease patients with lower initial aerobic fitness exhibit greater improvements in ventilatory efficiency with aerobic exercise training.METHOD:A total of 123 patients (61.0±0.7 years) with coronary artery disease were divided according to aerobic fitness status into 3 groups: group 1 (n = 34, peak VO2<17.5 ml/kg/min), group 2 (n = 67, peak VO2>17.5 and <24.5 ml/kg/min) and group 3 (n = 22, peak VO2>24.5 ml/kg/min). All patients performed a cardiorespiratory exercise test on a treadmill. Ventilatory efficiency was determined by the lowest VE/VCO2 ratio observed. The exercise training program comprised moderate-intensity aerobic exercise performed 3 times per week for 3 months. Clinicaltrials.gov: NCT02106533RESULTS:Before intervention, group 1 exhibited both lower peak VO2 and lower ventilatory efficiency compared with the other 2 groups (p<0.05). After the exercise training program, group 1 exhibited greater improvements in aerobic fitness and ventilatory efficiency compared with the 2 other groups (group 1: ▵ = -2.5±0.5 units; group 2: ▵ = -0.8±0.3 units; and group 3: ▵ = -1.4±0.6 units, respectively; p<0.05).CONCLUSIONS:Coronary artery disease patients with lower aerobic fitness status exhibited lower ventilatory efficiency during a graded exercise test. In addition, after 3 months of aerobic exercise training, only the patients with initially lower levels of aerobic fitness exhibited greater improvements in ventilatory efficiency.

RH-02 * A PILOT RCT ON THE EFFICACY OF HOME-BASED EXERCISE TO IMPROVE COGNITIVE FUNCTIONING IN GRADE II AND III GLIOMA PATIENTS

Many patients with gliomas suffer from cognitive deficits. Recent findings indicate that physical exercise is effective in ameliorating cognitive decline, in particular in older adults and select neurological patient populations. Studies of exercise interventions in patients with cancer demonstrated to have beneficial effects on various measures of physical and mental well-being. This pilot randomized controlled trial investigates the efficacy of home-based exercise in improving cognitive functioning and self-reported mental well-being in glioma patients. Clinically stable patients with grade II and III glioma will undergo baseline neuropsychological testing, including questionnaires on cognitive symptoms, fatigue, sleep, mood and quality of life; and cardiorespiratory exercise testing (CPET) to determine room for improvement of physical fitness. Sixty patients will be randomized in a 2:1 ratio to the intervention group or active control group. Patients in the intervention group exercise 3 times per week for 6 months, during 20 to 45 minutes at an increasing intensity of 55 to 85% of their maximum heart rate. CPET-outcome (VO2peak) is used to tailor an individual, home-based exercise program. Participants wear heart rate monitors and are supervised by a physical therapist via internet and telephone. Patients in the active control group are advised to walk regularly. Neuropsychological test performance, physical fitness, and mental well-being are assessed again after 6 months. In November 2014, 30 patients are expected to be accrued. Six-month follow-up data on neuropsychological performance, physical fitness and self-reported mental well-being of the currently included 15 patients (12 intervention; 3 control group) will be available. Mean age of this group is 48.1 (±9.8) years; median time since surgery is 4.1 (0.7-14.7) years. Most of these participants are female (n = 11), and have a grade II glioma (n = 10). To our knowledge, this is the first study that evaluates the effects of an exercise intervention in patients with gliomas.

Cardiorespiratory Fitness in Kidney Transplant Recipients.

PURPOSE Cardiorespiratory fitness (VO2max) garners little attention in kidney transplant recipients (KTRs). The primary objectives were to establish the prevalence, impact and predictors of reduced VO2max. The role of VO2max assessment in potential KTRs remains controversial. The secondary objective was to evaluate the prognostic value of pre-transplant cardiorespiratory exercise test. METHODS Primary objectives were tested by a cross-sectional cohort of KTRs ≥1 year post-transplantation (n=55; mean age=46±14 years; 58% male). Secondary objectives were tested by a longitudinal cohort of living-donor KTRs within 1 month pre-transplantation (n=26; mean age=41±16 years; 58% male). VO2max was estimated by submaximal exercise test. “Reduced” (≤0.81 predicted) and “severely reduced” (<0.62 predicted) VO2max were delineated. QoL was assessed with SF-36. Clinical outcome data were retrieved from medical records. Demographic, nutritional and clinical predictors of VO2max were assessed. RESULTS Mean KTRs' VO2max=26.7±9.0 ml/kg/min. “Reduced VO2max” was found in 58% of KTRs, with 22% being “severely reduced”. Post-transplant VO2max positively correlated with QoL (p<0.001), but did not predict 2-year hospitalisation rates and days to first hospitalisation. Predictors of reduced VO2max were female (p=0.004), increased fat mass (p=0.002), hypovolemia (p<0.001), and hypervolemia (p<0.001). In patients awaiting kidney transplantation, pre-transplant VO2max did not correlate with QoL up to 1 year post-transplantation, and did not predict 2-year hospitalisation rates and days to first hospitalisation post-transplantation. Similarly, pre-transplant VO2max did not predict early clinical outcomes within the 1st week post-transplantation including systolic and diastolic blood pressure, lowest standardised early warning score, creatinine reduction ratio, and length of hospital stay. No patient required dialysis, inotropes, and ICU admission within the 1st week post-transplantation. There was no incidence of delayed graft function. CONCLUSION Reduced cardiorespiratory fitness is common in KTRs, and is associated with reduced QoL. This study identified potential modifiable predictors, setting the scene for interventional studies. The limited predictive value of pre-transplant cardiorespiratory exercise testing on post-transplant QoL and early clinical outcomes needs further validation.

Heart rate recovery after the 10-m incremental shuttle walking test in older adults with intellectual disabilities

Heart rate recovery (HRR) after exercise is an independent predictor for cardiovascular and all-cause mortality. To investigate the usefulness of HRR in cardiorespiratory exercise testing in older adults with intellectual disabilities (ID), the aims of this study were (a) to assess HRR in older adults with ID after the 10-m incremental shuttle walking test (ISWT) and (b) its association with personal characteristics (gender, age, distance walked on the ISWT, level of ID, genetic syndrome causing ID, autism, behavioral problems, and peak heart rate (HRpeak)). HRR was assessed after the 10-m incremental shuttle walking test in 300 older adults (>50 years) with borderline to profound ID. HRR was defined as the change from HRpeak during the ISWT to heart rate measured after 1, 2, 3, 4, and 5 min of passive recovery. The largest decrease in heart rate was in the first minute of recovery leveling off toward the fifth minute of recovery. An abnormal HHR (≤12 bpm) was seen in 36.1% of the participants with Down syndrome (DS) and in 30.7% of the participants with ID by other causes. After the fifth minute the heart rates of 69.4% of the participants with DS and of 61.4% of the participants with ID by other causes returned to resting levels. HRpeak and distance walked on the ISWT were positively related to all HRR measures. More severe ID was negatively related and having DS positively related to HRR after 3-5 min of recovery. The other characteristics were not significantly associated to HRR. HRR is a potentially useful outcome measure in cardiorespiratory fitness testing of older adults with ID with a direct, objective, and non-invasive measurement. Further research is needed to identify the relation between HRR and adverse health outcomes in this population.

Determinants of maximal oxygen uptake (VO2 max) in fire fighter testing

The aim of this study was to evaluate current daily practice of aerobic capacity testing in Belgian fire fighters. The impact of personal and test-related parameters on the outcome has been evaluated.Maximal oxygen uptake (VO2 max) results of 605 male fire fighters gathered between 1999 and 2010 were analysed. The maximal cardio respiratory exercise tests were performed at 22 different centres using different types of tests (tread mill or bicycle), different exercise protocols and measuring equipment.Mean VO2 max was 43.3 (SD = 9.8) ml/kg.min. Besides waist circumference and age, the type of test, the degree of performance of the test and the test centre were statistically significant determinants of maximal oxygen uptake.Test-related parameters have to be taken into account when interpreting and comparing maximal oxygen uptake tests of fire fighters. It highlights the need for standardization of aerobic capacity testing in the medical evaluation of fire fighters.

Respiratory effects of silica inhalation among marble industry workers

Introduction: Among the currently disabling occupational diseases 60% are attributed to the respiratory system, with 85% of cases related to silicosis. Objective: This study assesses the respiratory effects of occupational silica inhalation among marble industry workers. Methods: 21 workers employed in the marble industry in the town if GurupiTO between March and May 2012 answered a questionnaire about their respiratory symptoms and smoking habits. All underwent spirometry. For intergroup comparison of smokers, ex-smokers, and nonsmokers the parametric ANOVA test was used and for other analyzes the nonparametric Fisher test, with a significance level of 5% probability. Results: The average age of workers was 27±6 years. The prevalence of symptomatic patients was 57%. Comparing the two groups for the presence or absence of symptoms by length of exposure to silica ( > or < than 5 years), smoking status, BMI, and spirometric variables obtained, there was no statistical significance. Conclusions: no association between the detected symptoms and exposure to silica could be identified. This does not exclude its probable interaction and reinforces the need for more specific studies, such as serial spirometry associated with lung volume analysis or cardiorespiratory fitness tests and exercise tests for a broader assessment targeted at these individuals.

Coronary Flow Reserve Predicts Cardiopulmonary Fitness in Patients with Coronary Artery Disease Independently of Systolic and Diastolic Function

Despite revascularization and optimal medical treatment, patients with coronary artery disease (CAD) have reduced exercise capacity. In the absence of coronary artery stenosis, coronary flow reserve (CFR) is a measure of coronary microvascular function, and a marker of future poor outcome in CAD patients. The aim of this study was to examine the relationship among CFR, systolic and diastolic function, peripheral vascular function, and cardiopulmonary fitness in CAD patients. Forty patients with median left ventricular ejection fraction (LVEF) 49 (interquartile 46-55) with documented CAD without significant left anterior descending artery (LAD) stenosis underwent cardiorespiratory exercise test with measurement of VO2 peak, digital measurement of endothelial function and arterial stiffness, and an echocardiography with measurement of LVEF using the biplane Simpson model, mitral early (E) and late (A) inflow velocities, and tissue Doppler diastolic (e') and systolic (s') velocities. Peak coronary flow velocity (CFV) was measured in the LAD using pulse-wave Doppler. CFR was calculated as the ratio between peak CFV at rest and during vasodilator stress. Median CFR was 2.22 (1.90-2.62) and VO2 peak was 21.8 (17.6-25.5). VO2 peak correlated significantly with CFR (r=0.57, P<0.001), E/e' (r=-0.35, P=0.04), and s' (r=0.41, P=0.01) and with LVEF (r=0.35, P=0.03). CFR remained independently associated with VO2 peak after adjustment for systolic and diastolic function. Coronary flow reserve measured noninvasively predicts cardiopulmonary fitness independently of resting systolic and diastolic function in CAD patients, indicating that cardiac output during maximal exercise is dependent on the ability of the coronary circulation to adapt to the higher metabolic demands of the myocardium.

Cardiorespiratory Fitness Predicts Mortality and Hospital Length of Stay After Major Elective Surgery in Older People

This study aimed to define the relationship between cardiorespiratory fitness and age in the context of postsurgery mortality and morbidity in older people. Postsurgery mortality and morbidity increase with age. Cardiorespiratory fitness also declines with age, and the independent and linked associations between cardiorespiratory fitness and age on postsurgical mortality and morbidity remain to be determined. An unselected consecutive group of 389 adults with a mean age of 66 years (range 26-86 years) underwent cardiorespiratory exercise testing before major hepatobiliary surgery at a single center. Mortality and critical care unit and hospital lengths of stay were collected from patient records. Primary outcomes were in-hospital all-cause mortality after surgery and hospital and critical care lengths of stay. Anaerobic threshold was the most significant independent predictor for postoperative mortality (P = 0.003; β = -0.657 and odds ratio = 0.52) in 18 of 389 (4.6%) patients who died during their in-hospital stay. Age was not a significant predictor in this model. Older people with normal cardiorespiratory fitness spent the same number of days in the hospital or critical care unit as younger people with similar cardiorespiratory fitness (13 vs 12; P = 0.08 and 1 vs 1; P = 0.103). Patients older than 75 years with low cardiorespiratory fitness spent a median of 11 days longer in hospital (23 vs 12; P < 0.0001) and 2 days longer in critical care (2.9 vs 0.9; P < 0.0001) when compared with patients with adequate cardiorespiratory fitness. Cardiorespiratory fitness is an independent predictor of mortality and length of hospital stay and provides significantly more accurate prognostic information than age alone. Clinicians should consider both the prognostic value of cardiorespiratory testing and techniques to preserve cardiorespiratory function before elective surgery in older people.