Category Archives: Abstracts

Elevated exercise ventilation in mild COPD is not linked to enhanced central chemosensitivity.

Phillips DB; Domnik NJ; Elbehairy AF; Preston ME; Milne KM; James MD; Vincent SG; Ibrahim-Masthan M; Neder JA; O’Donnell DE;

Respiratory physiology & neurobiology [Respir Physiol Neurobiol] 2020 Nov 05, pp. 103571. Date of Electronic Publication: 2020 Nov 05.

Background: The purpose of this study was to determine if altered central chemoreceptor characteristics contributed to the elevated ventilation relative to carbon dioxide production (V̇ E /V̇CO 2 ) response during exercise in mild chronic obstructive pulmonary disease (COPD).
Methods: Twenty-nine mild COPD and 19 healthy age-matched control participants undertook lung function testing followed by symptom-limited incremental cardiopulmonary exercise testing (CPET). On a separate day, basal (non-chemoreflex) ventilation (V̇ EB ), the central chemoreflex ventilatory recruitment threshold for CO 2 (VRTCO 2 ), and central chemoreflex sensitivity (V̇ ES ) were assessed using the modified Duffin’s CO 2 rebreathing method. Resting arterialized blood gas data were also obtained.
Results: At standardized exercise intensities, absolute V̇ E and V̇ E /V̇CO 2 were consistently elevated and the end-tidal partial pressure of CO 2 was relatively decreased in mild COPD versus controls (all p < 0.05). There were no between-group differences in resting arterialized blood gas parameters, basal V̇ E , VRTCO 2 , or V̇ ES (all p > 0.05).
Conclusion: These data have established that excessive exercise ventilation in mild COPD is not explained by altered central chemosensitivity.

Using heart rate to estimate the minute ventilation and inhaled load of air pollutants.

Guo Q; Zhao Y; Shao J; Cao S; Wang Q; Wu W;

The Science of the total environment [Sci Total Environ] 2020 Oct 19, pp. 143011. Date of Electronic Publication: 2020 Oct 19.

Background: The health effects of air pollution are associated with the concentration of pollutants and ventilation (VE). VE is difficult to measure directly and has been predicted by heart rate (HR). However, it is unclear whether equations between HR and VE obtained from a laboratory cardiopulmonary exercise test (CPET) can be extended to external groups and there is still a gap in their relationship for a Chinese population.
Objective: To establish an association between HR and VE in young Chinese individuals and verify the external validity of the model.
Methods: Eighty non-smoking participants aged 16-21 years underwent incremental tests using a bicycle ergometer, where the HR and minute VE were measured simultaneously. Linear mixed models were constructed with data obtained from a CPET. Ten individuals were chosen randomly as the external validation group. The predictive performance was assessed using an eight-fold cross-validation procedure. Air pollution concentration was monitored during the CPET and the inhaled load was calculated.
Results: The overall estimation of the intercept and slope for all participants was 0.585 ± 0.013 and 0.007 ± 0.00002, respectively. The overall fitted R squared (R 2 ) was 0.84. The median difference between the measured VE and the predicted VE was 0.3 L/min, and the difference between the inhaled load based on the fitted VE and the measured VE was 0.0-0.3 μg across all the participants. The eight folds cross-validation R 2 value was 0.78, suggesting high predictive accuracy.
Conclusion: This is the first study to derive a novel equation for the relationship between HR and VE in a young Chinese population and verify its external validity. This will be important in the assessment of the inhaled load in future epidemiology studies. However, inter-individual variations should also be considered when VE is estimated at an individual level.

Multidimensional breathlessness assessment during cardiopulmonary exercise testing in healthy adults.

Lewthwaite H; Jensen D;

European journal of applied physiology [Eur J Appl Physiol] 2020 Nov 03. Date of Electronic Publication: 2020 Nov 03.

Purpose: This study explored if healthy adults could discriminate between different breathlessness dimensions when rated immediately one after another (successively) during symptom-limited incremental cardiopulmonary cycle exercise testing (CPET) using multiple single-item rating scales.
Methods: Fifteen apparently healthy adults (60% male) aged 22 ± 2 years performed six incremental cycle CPETs separated by ≥ 48 h. During each CPET (at rest, every 2-min and at end exercise), participants rated different breathlessness sensations using the 0-10 modified Borg scale using one of six assessment protocols, randomized for order: (1) ‘BREATHLESS ALL ‘ = breathlessness sensory intensity (SI), breathlessness unpleasantness (UN), work/effort of breathing (SQ W/E ), and unsatisfied inspiration (SQ UI ) assessed; (2) SI and UN assessed; and (3-6) SI, UN, SQ W/E , and SQ UI each assessed alone. Physiological responses to CPET were also evaluated.
Results: Physiological and breathlessness responses to CPET were comparable across the six protocols, with the exception of SI rated lower at the highest submaximal power output (220 ± 56 watts) during the BREATHLESS ALL protocol (0-10 Borg units 4.2 ± 1.7) compared to SI + UN (5.2 ± 2.1, p = 0.03) and SI alone (5.1 ± 1.9, p = 0.04) protocols. Ratings of SI and SQ W/E were not significantly different when assessed in the same protocol, and were significantly higher than UN and SQ UI , which were comparable.
Conclusion: In healthy younger adults, use of two separate single-item rating scales to assess breathlessness during CPET is feasible and enables the distinct sensory intensity and affective dimensions of exertional breathlessness to be assessed.

Impact of exercise training and supplemental oxygen on submaximal exercise performance in patients with COPD.

Neunhäuserer D; Reich B; Mayr B; Kaiser B; Lamprecht B; Ermolao A; Studnicka M; Niebauer J;

Scandinavian journal of medicine & science in sports [Scand J Med Sci Sports] 2020 Nov 05. Date of Electronic Publication: 2020 Nov 05.

Functional impairment caused by chronic obstructive pulmonary disease (COPD) impacts on activities of daily living and quality of life. Indeed, patients’ submaximal exercise capacity is of crucial importance. It was the aim of this study to investigate the effects of an exercise training intervention with and without supplemental oxygen on submaximal exercise performance. This is a secondary analysis of a randomized, controlled, double-blind, crossover trial. 29 COPD patients (63.5±5.9 years; FEV 1 46.4±8.6%) completed two consecutive 6-week periods of high intensity interval cycling and strength training, which was performed three times/week with either supplemental oxygen or medical air (10 L/min). Submaximal exercise capacity as well as the cardiocirculatory, ventilatory and metabolic response were evaluated at isotime (point of termination in the shortest cardiopulmonary exercise test), at physical work capacity at 110 bpm of heart rate (PWC 110), at the anaerobic threshold (AT), and at the lactate-2 mmol/L threshold. After 12 weeks of exercise training, patients improved in exercise tolerance, shown by decreased cardiocirculatory (heart rate, blood pressure) and metabolic (respiratory exchange ratio, lactate) effort at isotime; ventilatory response was not affected. Submaximal exercise capacity was improved at PWC 110, AT and the lactate-2 mmol/L threshold, respectively. Although supplemental oxygen seems to affect patients’ work rate at AT and the lactate-2 mmol/L threshold, no other significant effects were found. The improved submaximal exercise capacity and tolerance might counteract patients’ functional impairment. Although cardiovascular and metabolic training adaptations were shown, ventilatory efficiency remained essentially unchanged. The impact of supplemental oxygen seems less important on submaximal training effects.

Evaluation of Fontan failure by classifying the severity of Fontan-associated liver disease: a single-centre cross-sectional study

Anastasia Schleiger  Peter Kramer  Madeleine Salzmann  Friederike Danne Stephan Schubert Christian Bassir Tobias Müller Frank Tacke  Hans-Peter Müller Felix Berger   Joachim Photiadis Stanislav Ovroutsk

Objectives: Fontan-associated liver disease (FALD) is a hallmark of the failing Fontan circulation, but no general classification of FALD severity exists. In this study, we propose a scoring system to grade the severity of FALD and analyse its applicability for evaluation of Fontan failure.
Methods: From 2017 to 2019, a total of 129 successive Fontan patients received a comprehensive hepatic assessment. The FALD score was based on results from laboratory testing, hepatic ultrasound and transient elastography by assigning scoring points for each abnormality detected. FALD severity was graded mild, moderate and severe. Haemodynamic assessment was performed using echocardiography, cardiopulmonary exercise testing and catheterization.

Results: FALD was graded absent/ mild, moderate and severe in 53, 26 and 50 patients, respectively. Cardiopulmonary capacity was significantly impaired in patients with severe FALD compared to patients with absent/mild FALD (P = 0.001). The FALD score significantly correlated with pulmonary artery pressure (P = 0.001), end-diastolic ventricular pressure (P < 0.001), hepatic venous pressure (P = 0.004) and wedged hepatic venous pressure (P = 0.009). Fontan failure was present in 21 patients. FALD was graded moderate in 2 and severe in 19 of these patients. The FALD score accurately discriminated patients with and without Fontan failure (sensitivity 90.5%, specificity 71.3%).
Conclusions: The FALD score significantly correlates with impaired Fontan haemodynamics. A cut-off value ≥6.0 has a high diagnostic accuracy in detecting Fontan failure.

Are our nurses healthy? Cardiorespiratory fitness in a very exhausting profession.

Sovová M; Sovová E; Nakládalová M; Pokorná T; Štégnerová L; Masný O; Moravcová K; Štěpánek L;

Central European journal of public health [Cent Eur J Public Health] 2020 Oct; Vol. 28 Suppl, pp. S53-S56.

Objectives: Low cardiorespiratory fitness (CRF) is related to higher risk of cardiovascular diseases, increase in all-cause mortality and higher risk of different tumors. The reverse is also true; improvement in CRF is related to decrease in mortality. Cardiopulmonary exercise testing (CPET) is a standard and also the most precise test for determination of CRF – the best possibility is the maximal test measuring different parameters including maximal oxygen consumption. Healthcare professionals throughout the developed world have markedly high rates of sickness absence, burnout, and distress compared to other sectors and this leads to higher risk factors. The study aimed to assess CRF in a group of nurses in a big hospital and compare it with population norms and available published results.
Methods: Nurses over 50 years of age working in one faculty hospital were gradually included in the study from the beginning of 2018. These nurses work in physically demanding positions. A CPET was carried out following the Bruce protocol.
Results: 90 nurses (84 females and 6 males), mean age 55.7 years, were evaluated by CPET. The resting blood pressure was within the norm in 58 persons (64.44%), maximal oxygen consumption in 61 persons (67.8%), W/kg in 25 persons (46.2%). We detected a hypertension reaction in 28 persons (31.1%), some types of arrhythmia in 17 persons (18.9%) and signs of ischaemia in 8 persons (8.9%). The result of CPET led to further examination in 42 persons (46.6%). Detailed examination resulted in change of medication in 21 nurses (23.3%). New diseases were diagnosed in 15 nurses (hypertension, atrial fibrillation, mitral valve prolapse indicated for cardiac surgery, coronary artery stenosis, and lipid disorders).
Conclusions: It was concluded that the usage of CPET during the regular medical check-ups significantly increases detection of hidden diseases and thus improves the care for nurses.

Does reduced cardiopulmonary exercise testing performance predict poorer quality of life in adult patients with Fontan physiology?

Suter B; Kay WA; Kuhlenhoelter AM; Ebenroth ES;

Cardiology in the young [Cardiol Young] 2020 Oct 21, pp. 1-7. Date of Electronic Publication: 2020 Oct 21.

Background: Cardiopulmonary exercise testing performance has been shown to be a predictor of morbidity, mortality, and quality of life in patients with Fontan physiology; however, the role of exercise performance along with other diagnostics is not fully understood. We evaluated the hypothesis that reduced exercise performance correlates with poorer quality of life in Fontan patients as they continue to age.
Methods: Chart review was performed on patients 12 years and older with Fontan who had completed cardiopulmonary exercise testing and age-appropriate quality of life surveys. Quality of life outcomes were analysed against exercise performance and other descriptive data.
Results: For the younger cohort (n = 22), exercise performance predicted quality of life with different measures across domains and had a stronger correlation than echocardiographic parameters. For the older cohort (n = 34), exercise performance did not predict quality of life.
Conclusions: Objective exercise performance was a useful marker for general, physical, emotional, social, and school quality of life in a younger cohort but less helpful in older adults. This is perhaps due to older patients accommodating to their conditions over time. The role of exercise performance and objective data in predicting quality of life in patients with Fontan physiology is incompletely understood and additional prospective evaluation should be undertaken.

Pitfalls in Expiratory Flow Limitation Assessment at Peak Exercise in Children: Role of Thoracic Gas Compression.

Strozza D; ; Wilhite DP; Babb TG; Bhammar DM

Medicine and science in sports and exercise [Med Sci Sports Exerc] 2020 Nov; Vol. 52 (11), pp. 2310-2319.

Purpose: Thoracic gas compression and exercise-induced bronchodilation can influence the assessment of expiratory flow limitation (EFL) during cardiopulmonary exercise tests. The purpose of this study was to examine the effect of thoracic gas compression and exercise-induced bronchodilation on the assessment of EFL in children with and without obesity.
Methods: Forty children (10.7 ± 1.0 yr; 27 obese; 15 with EFL) completed pulmonary function tests and incremental exercise tests. Inspiratory capacity maneuvers were performed during the incremental exercise test for the placement of tidal flow volume loops within the maximal expiratory flow volume (MEFV) loops, and EFL was calculated as the overlap between the tidal and the MEFV loops. MEFV loops were plotted with volume measured at the lung using plethysmography (MEFVp), with volume measured at the mouth using spirometry concurrent with measurements in the plethysmograph (MEFVm), and from spirometry before (MEFVpre) and after (MEFVpost) the incremental exercise test. Only the MEFVp loops were corrected for thoracic gas compression.
Results: Not correcting for thoracic gas compression resulted in incorrect diagnosis of EFL in 23% of children at peak exercise. EFL was 26% ± 15% VT higher for MEFVm compared with MEFVp (P < 0.001), with no differences between children with and without obesity (P = 0.833). The difference in EFL estimation using MEFVpre (37% ± 30% VT) and MEFVpost (31% ± 26% VT) did not reach statistical significance (P = 0.346).
Conclusions: Not correcting the MEFV loops for thoracic gas compression leads to the overdiagnosis and overestimation of EFL. Because most commercially available metabolic measurement systems do not correct for thoracic gas compression during spirometry, there may be a significant overdiagnosis of EFL in cardiopulmonary exercise testing. Therefore, clinicians must exercise caution while interpreting EFL when the MEFV loop is derived through spirometry.

Progress Update and Challenges on V.O2max Testing and Interpretation.

Martin-Rincon M; Calbet JAL;

Frontiers in physiology [Front Physiol] 2020 Sep 03; Vol. 11, pp. 1070. Date of Electronic Publication: 2020 Sep 03 (Print Publication: 2020).

The maximal oxygen uptake ( V.O2max ) is the primary determinant of endurance performance in heterogeneous populations and has predictive value for clinical outcomes and all-cause mortality. Accurate and precise measurement of V.O2max requires the adherence to quality control procedures, including combustion testing and the use of standardized incremental exercise protocols with a verification phase preceded by an adequate familiarization. The data averaging strategy employed to calculate the V.O2max from the breath-by-breath data can change the V.O2max value by 4-10%. The lower the number of breaths or smaller the number of seconds included in the averaging block, the higher the calculated V.O2max value with this effect being more prominent in untrained subjects. Smaller averaging strategies in number of breaths or seconds (less than 30 breaths or seconds) facilitate the identification of the plateau phenomenon without reducing the reliability of the measurements. When employing metabolic carts, averaging intervals including 15-20 breaths or seconds are preferable as a compromise between capturing the true V.O2max and identifying the plateau. In training studies, clinical interventions and meta-analysis, reporting of V.O2max in absolute values and inclusion of protocols and the averaging strategies arise as imperative to permit adequate comparisons. Newly developed correction equations can be used to normalize V.O2max to similar averaging strategies. A lack of improvement of V.O2max with training does not mean that the training program has elicited no adaptations, since peak cardiac output and mitochondrial oxidative capacity may be increased without changes in V.O2max .

Healthy Vascular Aging Is Associated With Higher Cardiorespiratory Fitness.

Fleenor BS; Carlini NA; Kaminsky LA; Whaley MH; Peterman JE; Harber MP

Journal of cardiopulmonary rehabilitation and prevention [J Cardiopulm Rehabil Prev] 2020 Oct 05. Date of Electronic Publication: 2020 Oct 05.

Background: Healthy vascular aging (HVA) and cardiorespiratory fitness (CRF) are each independently associated with lower cardiovascular disease-related mortality. It is unknown, however, whether the CRF-related reductions in cardiovascular disease risk are related to HVA. We hypothesized that HVA would be associated with higher CRF in men and women from the Ball State Adult Fitness Longitudinal Lifestyle STudy (BALL ST).
Methods: Apparently healthy men and women ≥50 yr of age from the BALL ST cohort (n = 101) who underwent a maximal cardiopulmonary exercise test to assess CRF (VO2peak) were included in the study. Participants were divided into either HVA, defined as brachial systolic blood pressure <140/90 mm Hg without taking medications and carotid-femoral pulse wave velocity <7.6 m/sec, or no HVA for subjects with SBP >140/90 mm Hg and/or PWV >7.6 m/sec.
Results: Participants with HVA had a higher age- and sex-adjusted CRF percentile (62 ± 5 vs 47 ± 3, P < .05), with women having a greater prevalence of HVA than men (36% vs 15%, P < .05). Both carotid-femoral pulse wave velocity (r =-0.27, P < .05) and brachial systolic blood pressure (r =-0.23, P < .05) were independently and inversely associated with CRF for the entire cohort. Men and women with HVA were younger having a lower body fat percentage and higher low-density lipoprotein cholesterol (P < .05, all).
Conclusions: These data demonstrate that HVA is associated with higher CRF, which may partially explain the preventative cardioprotective effects of CRF.