Progressive Cardiopulmonary Exercise Research Articles

Changes in pain perception during pregnancy after one-time maximal physical exertion and an 8-week high-intensity interval training.

Background: Pain, a subjective sensation, poses a great challenge to the human body as a stressor. There is empirical evidence that moderate to intense physical activity increases pain tolerance and this may be critical during pregnancy for optimal pregnancy, fetal development, and delivery. To the best of our knowledge, it is the first study examining the changes in pain perception in pregnant women after a maximal progressive exercise test and after 8weeks of high-intensity interval training (HIIT). Methods: Thirty-five women with uncomplicated singleton pregnancies between 13 and 28weeks of gestation participated in the study. The HIIT intervention was developed in accordance with the recommendations and available data on HIIT during pregnancy. The maximal progressive cardiopulmonary exercise test was performed on a cycle ergometer with an electronically controlled load. Pressure pain threshold and pressure pain tolerance were measured with an algometer. Results: We found significant effects of the maximal exercise test and high-intensity interval training, such that the pregnant women had higher pain tolerance after the maximal exercise test than before and after the high-intensity interval training than the baseline. Conclusion: Our results suggest that post-exercise analgesia may be important in pregnant women and that high-intensity interval training appears to be beneficial for pregnant women to improve their pain tolerance while being obstetrically safe. Increased pain tolerance before labor could lead to better management of pain during labor and in the postpartum and lactation periods. Increasing pregnant women's awareness of this issue can improve their wellbeing and provide more comfort during labor.

ATPase Inhibitory Factor 1-A Novel Marker of Cellular Fitness and Exercise Capacity?

ATPase inhibitory factor 1 is a myokine inhibiting the hydrolytic activity of mitochondrial adenosine triphosphate synthase and ecto-F1-ATPase on the surface of many cells. IF1 affects ATP metabolism in mitochondria and the extracellular space and upregulates glucose uptake in myocytes; these processes are essential in physical activity. It is unknown whether the IF1 serum concentration is associated with exercise capacity. This study explored the association between resting IF1 serum concentration and exercise capacity indices in healthy people. IF1 serum concentration was measured in samples collected at rest in 97 healthy amateur cyclists. Exercise capacity was assessed on a bike ergometer at the successive stages of the progressive cardiopulmonary exercise test (CPET). IF1 serum concentration was negatively and significantly correlated with oxygen consumption, oxygen pulse, and load at various CPET stages. A better exercise capacity was associated with lower circulating IF1. IF1 may reflect better cellular/mitochondrial energetic fitness, but there is uncertainty regarding how IF1 is released into the intravascular space. We speculate that lower IF1 concentration may reflect a better cellular/mitochondrial integrity, as this protein is bound more strongly with ATPases in mitochondria and cellular surfaces in people with higher exercise capacity.

Comparative effects of a cardiovascular rehabilitation program on functional capacity in patients with chronic chagasic cardiomyopathy with or without heart failure

Purpose The aim of the present study was to evaluate the effects of cardiovascular rehabilitation (CR) on functional capacity of patients with chronic chagasic cardiomyopathy (CCC) and to compare the responses between CCC patients without and with heart failure (HF). Materials and methods A longitudinal observational retrospective study was carried out including 36 patients with CCC without HF (stage B2 [n = 7]) and with HF (stage C [n = 29]), who participated in a CR program. Functional capacity was assessed by a maximal progressive cardiopulmonary exercise test performed on a treadmill. The longitudinal effects of the CR on functional capacity were determined by linear mixed models that included an interaction term to evaluate the differential responses between patients without and with HF. Results Significant improvements in peak oxygen consumption, resting heart rate and blood pressure, and maximum pulmonary ventilation were observed for the overall study sample, with no apparent differential effects according to the presence of HF. Conclusions CR significantly improved functional capacity of patients with CCC. The responses to CR appear to be similar among patients without and with HF, reinforcing the need for its inclusion as a standard treatment strategy of CCC. Implications for rehabilitation Exercise-based cardiovascular rehabilitation (CR) is a safe strategy that improves functional capacity, cardiac function, and quality of life in patients with several cardiovascular diseases, and recent studies also suggested a potential beneficial effect of CR in chronic chagasic cardiomyopathy (CCC). In this observational study, CR seems to equally improve exercise capacity, resting heart rate, resting blood pressure, and maximum pulmonary ventilation in patients with CCC without (stage B2) and with heart failure (stage C). Cardiovascular rehabilitation should be included as a standard treatment strategy for patients with CCC, regardless the severity of cardiomyopathy.

Factors related to the discontinuation and mortality rates of a cardiac rehabilitation programme in patients with Chagas disease: a 6-year experience in a Brazilian tertiary centre.

To describe the clinical and sociodemographic characteristics of participants as well as discontinuation and mortality rates in a cardiac rehabilitation programme (CRP) tailored to Chagas disease (CD). Participants underwent functional capacity, anthropometry and cardiac function evaluations before beginning a CRP. Univariate and multivariate Cox proportional hazards models were performed to investigate the associations between clinical and sociodemographic characteristics at baseline with discontinuation rates and deaths. Forty-two patients were enrolled in the CRP (61.9% men, mean age of 58.1±11.8years). During a median follow-up period of 10.8months, 74% discontinued and 14% died while enrolled in CRP. 34% of the patients who discontinued CRP died during follow-up. White race (HR=0.09; 95% CI 0.01-1.00), right ventricular systolic dysfunction (HR=10.54; 95% CI 1.24-89.50) and oxygen pulse (HR=0.69; 95% CI 0.48-0.99) were independently associated with death while enrolled in CRP. Married status (HR=0.44; 95% CI 0.21-0.95) was independently associated with discontinuation rates from CRP. VO2 peak (HR=0.85; 95% CI 0.74-0.98) and CRP discontinuation due to CD-related reasons (HR=8.33; 95% CI 1.91-36.27) were the variables independently associated with death after discontinuation of CRP. In this population, sociodemographic aspects and severity of CD were important determinants of CRP discontinuation and mortality.

Accurate assessment of cardiopulmonary fitness and analysis of its related factors in stroke patients

To accurately assess cardiopulmonary fitness of stroke patients and to analyze its related factors. The basic data of 38 stroke patients, such as age, sex, height, etc., were collected. Fugl–Meyer, MMSE, ADL, and Berg scales were used to evaluate their exercise function, cognitive function, daily activity and balance function. All the patient used the power bicycle to carry out the maximum progressive cardiopulmonary exercise test with a restrictive symptom, and data on cardiopulmonary index, subjective fatigue, heart rate, blood pressure and other data were collected. Single factor analysis and multiple factors logistics regression analysis of cardiopulmonary fitness in stroke patients were carried out by SPSS 17.0 statistical software to explore the factors affecting the cardiopulmonary fitness. Thirty-eight stroke patients enrolled in the study were able to complete the cardiopulmonary exercise test without adverse events. Cardiopulmonary fitness significantly decreased (VO 2 peak was 12.89 + 3.42 mL/kg/min). Single factor analysis showed that age, sex, Fugl–Meyer, MMSE, ADL, bad habits and daily exercise habits were the influencing factors of cardiopulmonary fitness in stroke patients ( P < 0.05). Multiple factor logistic regression analysis showed that high Fugl–Meyer score, high MMSE score and regular exercise habit were independent protective factors of cardiopulmonary fitness (OR < 1), while advanced age, women and bad living habits were their independent risk factors (OR > 1). Cardiopulmonary fitness significantly decreases in stroke patients. High Fugl–Meyer score, high MMSE score and regular exercise habit are independent protective factors of cardiopulmonary fitness, while advanced age, women and bad living habits are its independent risk factors.

The Use of a Wheelchair Propulsion Field Test to Determine Peak Heart Rate in Children and Adolescents With Myelomeningocele.

We analyzed the evolution and pattern of heart rate (HR) during the 12-minute wheelchair propulsion field test (WPFT) and compared the peak HR (HRpeak) from the WPFT to the HRpeak obtained in the progressive cardiopulmonary exercise test on arm cranking ergometer (ACT). We aimed to determine if the field test detects the HRpeak consistently and could be used in clinical practice. Eleven wheelchair-using children and adolescents with myelomeningocele (aged 8-15y) performed a maximal ACT and a 12-minute WPFT. HR was recorded continuously at rest, during each minute of the tests, and at recovery. Mixed analysis of variance was used to compare the variables at rest and peak. Bland-Altman plot and Lin's concordance correlation coefficient were used to show agreement between the tests. During minute 2 of the WPFT, participants reached 73%-96% of the HRpeak values recorded in the ACT. From minutes 4 to 12, participants reached HRpeak values ranging 86%-109% of the values recorded in the ACT. There is agreement between the ACT and the WPFT tests. WPFT with minimal duration of 4minutes may be an alternative tool to obtain HRpeak in children and adolescents with myelomeningocele.

The six-minute walk test predicts cardiorespiratory fitness in individuals with aneurysmal subarachnoid hemorrhage

Background: Peak oxygen uptake (VO2peak) established during progressive cardiopulmonary exercise testing (CPET) is the “gold-standard” for cardiorespiratory fitness. However, CPET measurements may be limited in patients with aneurysmal subarachnoid hemorrhage (a-SAH) by disease-related complaints, such as cardiovascular health-risks or anxiety. Furthermore, CPET with gas-exchange analyses require specialized knowledge and infrastructure with limited availability in most rehabilitation facilities.Objectives: To determine whether an easy-to-administer six-minute walk test (6MWT) is a valid clinical alternative to progressive CPET in order to predict VO2peak in individuals with a-SAH.Methods: Twenty-seven patients performed the 6MWT and CPET with gas-exchange analyses on a cycle ergometer. Univariate and multivariate regression models were made to investigate the predictability of VO2peak from the six-minute walk distance (6MWD).Results: Univariate regression showed that the 6MWD was strongly related to VO2peak (r = 0.75, p < 0.001), with an explained variance of 56% and a prediction error of 4.12 ml/kg/min, representing 18% of mean VO2peak. Adding age and sex to an extended multivariate regression model improved this relationship (r = 0.82, p < 0.001), with an explained variance of 67% and a prediction error of 3.67 ml/kg/min corresponding to 16% of mean VO2peak.Conclusions: The 6MWT is an easy-to-administer submaximal exercise test that can be selected to estimate cardiorespiratory fitness at an aggregated level, in groups of patients with a-SAH, which may help to evaluate interventions in a clinical or research setting. However, the relatively large prediction error does not allow for an accurate prediction in individual patients.

Using Pre-Exercise Photobiomodulation Therapy Combining Super-Pulsed Lasers and Light-Emitting Diodes to Improve Performance in Progressive Cardiopulmonary Exercise Tests.

Skeletal muscle fatigue and exercise performance are novel areas of research and clinical application in the photobiomodulation field, and positive outcomes have been reported in several studies; however, the optimal measures have not been fully established. To assess the acute effect of photobiomodulation therapy (PBMT) combining superpulsed lasers (low-level laser therapy) and light-emitting diodes (LEDs) on muscle performance during a progressive cardiopulmonary treadmill exercise test. Crossover study. Laboratory. Twenty untrained male volunteers (age = 26.0 ± 6.0 years, height = 175.0 ± 10.0 cm, mass = 74.8 ± 10.9 kg). Participants received PBMT with either combined superpulsed lasers and LED (active PBMT) or placebo at session 1 and the other treatment at session 2. All participants completed a cardiopulmonary test on a treadmill after each treatment. For active PBMT, we performed the irradiation at 17 sites on each lower limb (9 on the quadriceps, 6 on the hamstrings, and 2 on the gastrocnemius muscles), using a cluster with 12 diodes (four 905-nm superpulsed laser diodes with an average power of 0.3125 mW, peak power of 12.5 W for each diode, and frequency of 250 Hz; four 875-nm infrared LED diodes with an average power of 17.5 mW; and four 640-nm red LED diodes with an average power of 15 mW) and delivering a dose of 30 J per site. Distance covered, time until exhaustion, pulmonary ventilation, and dyspnea score. The distance covered (1.96 ± 0.30 versus 1.84 ± 0.40 km, t19 = 2.119, P < .001) and time until exhaustion on the cardiopulmonary test (780.2 ± 91.0 versus 742.1 ± 94.0 seconds, t19 = 3.028, P < .001) was greater after active PBMT than after placebo. Pulmonary ventilation was greater (76.4 ± 21.9 versus 74.3 ± 19.8 L/min, t19 = 0.180, P = .004) and the score for dyspnea was lower (3.0 [interquartile range = 0.5-9.0] versus 4.0 [0.0-9.0], U = 184.000, P < .001) after active PBMT than after placebo. The combination of lasers and LEDs increased the time, distance, and pulmonary ventilation and decreased the score of dyspnea during a cardiopulmonary test.

Impaired cardiorespiratory fitness after aneurysmal subarachnoid hemorrhage.

To assess cardiorespiratory fitness in patients following an aneurysmal subarachnoid haemorrhage and to explore this in fatigued and non-fatigued patients. Cross-sectional case-control study. A total of 28 patients, 6 months post aneurysmal subarachnoid haemorrhage, and 28 sex- and age-matched controls. Cardiorespiratory responses to a progressive cardiopulmonary exercise test on a cycle ergometer were obtained using indirect calorimetry. Fatigue was assessed using the Fatigue Severity Scale. Mean peak oxygen uptake (V̇O2peak) was significantly lower in patients (22.0 (standard deviation (SD) 6.2) ml/kg/min) than in controls (69% of controls, p < 0.001). All other cardiorespiratory fitness parameters were also lower, with peak levels ranging from 62% to 77% of matched controls. Mean V̇O2peak was 19.4 (SD 4.1) ml/kg/min in fatigued patients (63% of matched controls, p < 0.001) and 23.9 (SD 6.9) ml/kg/min in non-fatigued patients (74% of matched controls, p = 0.002). Cardiorespiratory fitness is impaired after aneurysmal subarachnoid haemorrhage, both in fatigued and non-fatigued patients. This finding may have implications for treatment.

Response profiles of oxygen uptake efficiency during exercise in healthy children.

Oxygen uptake efficiency (OUE), the relation between oxygen uptake (VO2) and minute ventilation (VE), differs between healthy children and children with heart disease. This study aimed to investigate the normal response profiles of OUE during a progressive cardiopulmonary exercise test. Cross-sectional. Healthy children between eight and 19 years of age (114 boys and 100 girls, mean ± SD age 12.7 ± 2.8 years) performed a maximal cardiopulmonary exercise test. Peak VO2 (VO2peak), ventilatory threshold and peak VE were determined. OUE was determined by the OUE plateau (OUEP), OUE at the ventilatory threshold (OUE@VT) and OUE slope (OUES). OUEP (42.4 ± 4.6) and OUE@VT (41.9 ± 4.7) were similar and less variable than OUES (2138 ± 703). OUEP correlated strongly with OUE@VT (r = 0.974); however, OUEP was weak-to-moderately correlated with VO2peak (r = 0.646), the ventilatory threshold (r = 0.548) and OUES (r = 0.589). OUES correlated strongly with VO2peak (r = 0.948) and the ventilatory threshold (r = 0.856). Reference centiles for OUEP show an almost linear increase from about 37 in eight-year olds to about 47 in 18-year olds, with no sex-difference. OUES increased from about 1400 in eight-year-old boys to approximately 3500 in 18-year-old boys. OUES increased from roughly 1250 in eight-year-old girls to about 2650 in 18-year-old girls. This study provides sex- and age-related normative values for both OUEP and OUES, which facilitates the interpretation of OUE in children. OUEP and OUES are objective and non-invasive cardiopulmonary exercise test parameters which do not require a maximal effort and might be indicative of cardiorespiratory function during exercise.

Ventilatory response to exercise in adolescents with cystic fibrosis and mild-to-moderate airway obstruction.

Data regarding the ventilatory response to exercise in adolescents with mild-to-moderate cystic fibrosis (CF) are equivocal. This study aimed to describe the ventilatory response during a progressive cardiopulmonary exercise test (CPET) up to maximal exertion, as well as to assess the adequacy of the ventilatory response for carbon dioxide (CO2) exhalation. Twenty-two adolescents with CF (12 boys and 10 girls; mean ± SD age: 14.3 ± 1.3 years; FEV1: 78.6 ± 17.3% of predicted) performed a maximal CPET. For each patient, data of a sex- and age matched healthy control was included (12 boys and 10 girls; mean ± SD age: 14.3 ± 1.4 years). At different relative exercise intensities of 25%, 50%, 75%, and 100% of peak oxygen uptake (VO2peak), breathing pattern, estimated ventilatory dead space ventilation (VD/VT ratio), minute ventilation (VE) to CO2 production relationship (VE/VCO2-slope), partial end-tidal CO2 tension (PETCO2), and the VE to the work rate (VE/WR) ratio were examined. VO2peak was significantly reduced in CF patients (P = 0.01). We found no differences in breathing pattern between both groups, except for a significantly higher VE at rest and a trend towards a lower VE at peak exercise in patients with CF. Significantly higher values were found for the estimated VD/VT ratio throughout the CPET in CF patients (P < 0.01). VE/VCO2-slope and PETCO2 values differed not between the two groups throughout the CPET. VE/WR ratio values were significantly higher in CF during the entire range of the CPET (P < 0.01). This study found an exaggerated ventilatory response (high VE/WR ratio values), which was adequate for CO2 exhalation (normal VE/VCO2-slope and PETCO2 values) during progressive exercise up to maximal exhaustion in CF patients with mild-to-moderate airway obstruction.

Modified Chrispin-Norman Score: Correlation With Peak Exercise Capacity and Efficiency of Ventilation in Children With Cystic Fibrosis

The modified Chrispin-Norman radiography score (CNS) is used in evaluation of radiographic changes in children with cystic fibrosis (CF). We evaluated the correlation of modified CNS with peak exercise capacity (Wpeak) and ventilatory efficiency (reflected by breathing reserve index-BRI) during progressive cardiopulmonary exercise testing (CPET). Thirty-six children aged 8-17 years were stratified according to their CNS into 3 groups: mild (<10), moderate (10-15), and severe (>15). CPET was performed on a cycle ergometer. Lung function tests included spirometry and whole-body plethysmography. Patients with higher CNS had lower FEV1 (p < .001), Wpeak predicted (%; p = .01) and lower mean peak oxygen consumption (VO2peak/kg; p = .014). The BRI at the anaerobic threshold and at Wpeak was elevated in patients with the highest CNS values (p < .001). The modified CNS correlates moderately with Wpeak (R = -0.443; p = .007) and BRI (R = -0.419; p = .011). Stepwise multiple linear regression showed that RV/TLC was the best predictor of Wpeak/pred (%; B = -0.165;  = -0.494; R2 = .244; p = .002). Children with CF who have high modified CNS exhibit decreased exercise tolerance and ventilatory inefficacy during progressive effort.

Different ventilatory responses to progressive maximal exercise test performed with either the arms or legs

OBJECTIVE:This study aimed to compare respiratory responses, focusing on the time-domain variability of ventilatory components during progressive cardiopulmonary exercise tests performed on cycle or arm ergometers.METHODS:The cardiopulmonary exercise tests were conducted on twelve healthy volunteers on either a cycle ergometer or an arm ergometer following a ramp protocol. The time-domain variabilities (the standard deviations and root mean squares of the successive differences) of the minute ventilation, tidal volume and respiratory rate were calculated and normalized to the number of breaths.RESULTS:There were no significant differences in the timing of breathing throughout the exercise when the cycle and arm ergometer measurements were compared. However, the arm exercise time-domain variabilities for the minute ventilation, tidal volume and respiratory rate were significantly greater than the equivalent values obtained during leg exercise.CONCLUSION:Although the type of exercise does not influence the timing of breathing when dynamic arm and leg exercises are compared, it does influence time-domain ventilatory variability of young, healthy individuals. The mechanisms that influence ventilatory variability during exercise remain to be studied.

Reversal of periodic breathing after aerobic training in heart failure

To the Editors: A 58-yr-old male was referred for participation in a cardiac rehabilitation programme. He had a long-term history of hypertensive cardiomyopathy and systolic dysfunction and was clinically stable, being treated with β-blocker carvedilol, losartan, digitalis, diuretics and spironolactone, with no changes in medication in the previous 16 weeks. An echocardiogram showed a 17% left ventricular ejection fraction and the patient was in New York Heart Association Functional Class III. Before starting the exercise training programme, the patient was submitted to a maximal progressive cardiopulmonary exercise test, on an electromagnetically braked cycle ergometer (Medifit 400L; Medical Fitness Equipment, Maarn, The Netherlands), with work rate increments of 5 W every 1 min at 60 rpm until exhaustion. Oxygen uptake ( V′ O2) and carbon dioxide production were determined by means of gas exchange on a breath-by-breath basis in a computerised system (Vmax 229 model; SensorMedics, BuenaVista, CA, USA). Peak V′ O2 was defined as the maximum attained V′ O2 at the end of the exercise period in which the patient could no longer maintain the cycle rate. During this test, the patient showed a very low exercise capacity, with a peak V′ O …

Laser (and LED) Therapy Is Phototherapy

Laser (and LED) Therapy Is Phototherapy

Exercise Intolerance Following Heart Transplantation: The Role of Pulmonary Diffusing Capacity Impairment

Although impairment of the diffusing capacity of the lung for carbon monoxide (DLCO) in heart transplant recipients is well-documented, there are limited data on its impact on exercise capacity in these patients. The aim of this study was to determine the effect of DLCO reduction on exercise capacity in heart transplant recipients. Descriptive cohort study. A regional cardiopulmonary transplant center. Twenty-six heart transplant recipients who were studied before and after transplantation compared with 26 healthy volunteers. Spirometry and static lung volumes were measured using body plethysmography, DLCO was measured using the single-breath technique, and progressive cardiopulmonary exercise was performed using a bicycle ergometer, continuous transcutaneous blood gas monitoring, and on-line analysis of minute ventilation, oxygen uptake (VO(2)), and carbon dioxide production. Before transplantation, the mean percent predicted for hemoglobin-corrected DLCO was reduced in patients (73.2%) compared to healthy control subjects (98.8%; p < 0.001) and declined significantly after transplantation (60.1%; p < 0.05). Although the mean maximal symptom-limited VO(2) (VO(2)max) increased after transplantation (increase, 41.3 to 48.6% of predicted; p < 0.05), it remained substantially lower than normal (92.9%; p < 0.001). There was a significant correlation between DLCO and VO(2)max after transplantation (r = 0.61; p = 0.001), but not before transplantation (r = 0.09; p = 0.66). DLCO was also inversely correlated with other respiratory responses to exercise, including the following: the ventilatory response to exercise (r = -0.44; p < 0.05); dead space to tidal volume ratio (r = -43; p < 0.05); and the alveolar-arterial oxygen gradient (r = -0. 45; p < 0.05), but there was no correlation between any of these variables and DLCO before transplantation. DLCO reduction after heart transplantation appears to represent persistent gas exchange impairment and contributes to exercise limitation in heart transplant recipients.

Recovery From Blast Lung Injury: One-Year Follow-up

Blast injury to the lung is one of the devastating threats facing victims of an explosion. Although the pathogenesis of blast injury has been studied, little is known about the long-term effects on lung function in survivors. To examine the pulmonary function of survivors 1 year after sustaining a blast injury. Prospective study. Pulmonary function test laboratory at Hadassah Medical Center, Jerusalem. Eleven surviving victims of a blast injury sustained during a bus terrorist explosion. Twelve months after the injury, physical examinations, lung function tests, and progressive cardiopulmonary exercise examinations were conducted, and chest radiographs were obtained. The average age was 28 +/- 9.8 years. Most of the victims had multiple injuries in addition to the lung injury. Ten patients received mechanical ventilation, and 6 patients required chest drainage. All patients were treated in the ICU, with an average stay of 11.8 +/- 9 days. The patients were discharged to their homes or to a rehabilitation center 32.4 +/- 27. 3 days after the explosion. One year later, none had any pulmonary-related complaints. Physical examination of the lungs was normal. Most of the patients demonstrated normal lung function tests and complete resolution of the chest radiograph findings. Most patients who survive lung blast injury will regain good lung function within a year.