Category Archives: Abstracts

Prediction for blood lactate during exercise using an artificial intelligence-Enabled electrocardiogram: a feasibility study.

Huang SC; Department of Physical Medicine and Rehabilitation, New Taipei Municipal Tucheng Hospital,  Taiwan.;
Lee CH; Hsu CC; Chang SY; Chen YA; Chiu CH; Hsiao CC; Su HR; S

Frontiers in physiology [Front Physiol] 2023 Oct 25; Vol. 14, pp. 1253598.
Date of Electronic Publication: 2023 Oct 25 (Print Publication: 2023).

Introduction: The acquisition of blood lactate concentration (BLC) during exercise is beneficial for endurance training, yet a convenient method to measure it remains unavailable. BLC and electrocardiogram (ECG) both exhibit variations with changes in exercise intensity and duration. In this study, we hypothesized that BLC during exercise can be predicted using ECG data.
Methods: Thirty-one healthy participants underwent four cardiopulmonary exercise tests, including one incremental test and three constant work rate (CWR) tests at low, moderate, and high intensity. Venous blood samples were obtained immediately after each CWR test to measure BLC. A mathematical model was constructed using 31 trios of CWR tests, which utilized a residual network combined with long short-term memory to analyze every beat of lead II ECG waveform as 2D images. An artificial neural network was used to analyze variables such as the RR interval, age, sex, and body mass index.
Results: The standard deviation of the fitting error was 0.12 mmol/L for low and moderate intensities, and 0.19 mmol/L for high intensity. Weighting analysis demonstrated that ECG data, including every beat of ECG waveform and RR interval, contribute predominantly.
Conclusion: By employing 2D convolution and artificial neural network-based methods, BLC during exercise can be accurately estimated non-invasively using ECG data, which has potential applications in exercise training.
Competing Interests: Author H-RS are employed by Super Genius Aitak Co., LTD. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Is Cardiopulmonary Exercise Testing Predictive of Surgical Complications in Patients Undergoing Surgery for Ovarian Cancer?

Smits A; Northern Gynaecological Oncology Centre, Queen Elizabeth Hospital, Gateshead NE9 6SX, UK.;
Agius CM; Blake D; Ang C; Kucukmetin A; Ham MV; Pijnenborg JMA; Knight J; Rundle S

Cancers [Cancers (Basel)] 2023 Oct 28; Vol. 15 (21).
Date of Electronic Publication: 2023 Oct 28.

Preoperative cardiopulmonary exercise testing (CPET) provides an objective assessment of functional capability. In other intra-abdominal surgical specialties, CPET outcomes are predictive of operative morbidity. However, in ovarian cancer surgery, its predictive value remains unknown. In this study, we evaluated the association between CPET performance and surgical morbidity in ovarian cancer patients. Secondly, we assessed the association between CPET performance and other surgical outcomes (i.e., hospital stay, readmission and residual disease). This was a retrospective cohort study of patients undergoing primary surgery for ovarian cancer between 2020 and 2023. CPET performance included peak oxygen uptake (VO2 max), ventilatory efficiency (VE/VO2 ) and anaerobic threshold. Outcomes were operative morbidity and included intra- and postoperative complications (Clavien-Dindo), hospital stay, readmission within 30 days and residual disease. A total of 142 patients were included. A lower VO2 peak and a higher VE/VCO2 were both associated with the occurrence of postoperative complications, and a poorer anaerobic threshold was associated with more transfusions. VE/VCO2 remained significantly associated after multivariate analysis ( p = 0.035). None of the CPET outcomes were associated with length of stay, readmission or residual disease. In conclusion, VE/VCO 2 was significantly associated with an increased risk of all-cause postoperative complications in ovarian cancer patients undergoing primary surgery.

 

Sports despite masks: no negative effects of FFP2 face masks on cardiopulmonary exercise capacity in children.

Weigelt A; Department of Pediatric Cardiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
Schöffl I; Rottermann K; Wällisch W; Müller SK; Dittrich S; Hübner MJ

European journal of pediatrics [Eur J Pediatr] 2023 Nov 11.
Date of Electronic Publication: 2023 Nov 11.

Face masks were recognized as one of the most effective ways to prevent the spread of the COVID-19 virus in adults. These benefits were extended to children and adolescents. However, the fear of negative consequences from wearing a face mask during physical exercise led to cancellations of physical education lessons. This further decreased the amount of physical activity available to children and adolescents during the pandemic. However, there is little published data on the potential adverse effects of wearing the most effective and partially mandatory FFP2/N95 face masks during PE or physical activity (PA) in this age. Even though the pandemic has been declared as passed by the WHO, the rise of a new pandemic and thus the use of face masks for limiting its spread is inevitable, so we need to be better prepared for alternative options to lockdown and limitation of PA in such a scenario. Twenty healthy children aged 8-10 years performed two identical cardiopulmonary exercise tests as an incremental step test on a treadmill within an interval of 2 weeks, one time without wearing a protective mask and one time wearing an FFP2 mask. The cardiopulmonary exercise parameter and especially the end-expiratory gas exchange for oxygen and carbon dioxide (petO 2 and petCO 2 ) were documented for each step, at rest and 1 min after reaching physical exhaustion. Twelve boys (mean age 8.5 ± 1.4 years) and 8 girls (mean age 8.8 ± 1.4 years) showed no adverse events until maximal exertion. The mean parameters measured at peak exercise did not differ significantly between both examinations (mean peak VO 2  = 42.7 ± 9.5 vs 47.8 ± 12.9 ml/min/kg, p = 0.097, mean O 2 pulse 7.84 ± 1.9 ml/min vs. 6.89 ± 1.8, p = 0.064, mean VE/VCO 2 slope 33.4 ± 5.9 vs. 34.0 ± 5.3, p = 0.689). The only significant difference was the respiratory exchange rate (RER, 1.01 ± 0.08 vs 0.95 ± 0.08, p = 0.004). The measured respiratory gases (end-tidal O 2 and CO 2 ) decreased and respectively increased significantly in almost every step when wearing an FFP2 mask. However, these levels were well below hypercapnia and above hypoxia.
Conclusion:  In this study, no significant differences in the cardiorespiratory function at peak exercise could be discerned when wearing an FFP2/N95 face mask. While the end-tidal values for CO 2 increased significantly and the end-tidal values for O 2 decreased significantly, these values did never reach levels of hypercapnia or hypoxia. Furthermore, the children terminated the exercise at a lower RER and heart rate (HR) suggesting a subconscious awareness of the higher strain. Since the detrimental effects of limiting sports during the pandemic are well documented, stopping PE lessons altogether because of the minor physiological effects of wearing these masks instead of simply stopping pushing children to perform at their best seems premature and should be reconsidered in the future.
What Is Known: • Wearing a face mask has an influence on psychological, social, and physiological functions in adults. • Because of the observed effects of wearing face masks in adults, physical activity in children was limited during the pandemic.
What Is New: • Wearing an FFP2/N95 mask during physical activity did not lead to hypercapnia or hypoxia in children in this study. • Even though end-tidal CO2 values were significantly higher and end-tidal O2 values significantly lower when wearing an FFP2/N95 face mask, no pathological values were reached.

Evaluation of Hydration Status by Bioelectrical Impedance Vector Analysis in Patients with Ischemic Heart Disease Undergoing Exercise Stress Test.

Juan Antonio PJ; Regenerative Medicine and Tissue Engineering Laboratory;  Centro Médico Nacional ISSSTE.
Dulce María NO; Juan Antonio SC; Jorge Antonio LV; José Rodolfo AM; Hugo Alberto RA; Eduardo Alfonso LV; Julieta Danira MP; Enrique GÁ; Brenda SJ; Paul MT;

Journal of visualized experiments : JoVE [J Vis Exp] 2023 Sep 22 (199).
Date of Electronic Publication: 2023 Sep 22.

Ischemic heart disease (IHD) represents a group of clinical syndromes characterized by myocardial ischemia, leading to an impairment in the myocardial blood supply and compromised perfusion. Several clinical variables assessed through a stress test, such as oxygen uptake (VO2) and heart rate oxygen pulse (HR/O2), have been attributed as cardiopulmonary prognostic factors in patients with IHD. However, other factors like hydration status (HS), potentially affecting the cardiopulmonary response, have been barely addressed. Unbalanced HS has a short-term effect on plasma volume and the sympathetic nervous system, which impacts blood volume, and lowers VO2 and HR/O2. Recently, bioelectrical impedance analysis (BIA), a method based on the opposition of body tissues (including fluid volume) to a low electrical current, has been widely used to assess HS by obtaining two components: resistance (R) and reactance (Xc) and using prediction formulas. However, several limitations as chronic illness or abnormal fluid status, may affect the results. In this sense, alternative BIA methods, such as bioelectrical impedance vector analysis (BIVA), have become relevant. R and Xc (adjusted by height) result in a vector plotted on the R/Xc graph, which allows interpreting the HS as normal or abnormal according to the distance of the mean vector. This study aims to describe how to determine HS by BIVA using a single-frequency device and compare the results with the cardiopulmonary response in patients with IHD.

Reproducibility of cardiopulmonary exercise testing between one after and 1-3 weeks after elective percutaneous coronary intervention.

Tanaka R; Division of Cardiovascular Rehabilitation, Okayama Heart Clinic, Okayama, Japan.
Waki I; Kamikawa S; Yamashita D; Tabita N; Nishimura S; Higashiya S; Yamaji H; Murakami T; Kusachi S;

Journal of exercise rehabilitation [J Exerc Rehabil] 2023 Oct 25; Vol. 19 (5), pp. 268-274.
Date of Electronic Publication: 2023 Oct 25 (Print Publication: 2023).

Prompt prescription and early initiation of exercise training are essential for patients undergoing elective percutaneous coronary intervention (PCI). We hypothesized that cardiopulmonary exercise testing (CPET) parameters determined the day after elective PCI during hospitalization would not differ from those obtained 1-3 weeks post-PCI in patients with stable coronary heart disease (CHD).
CPET was performed the day after and 1-3 weeks (13±4.6; 7-21 days) after PCI. CPET was performed with a bicycle ergometer up to the ventilatory aerobic threshold (VAT) on the day after PCI. Symptom-limited CPET was conducted 1-3 weeks after PCI. No complications arose from the tests. There were no significant differences in %VAT (next day: 88.6±16.7 vs. 1-3 weeks later: 91.4%±18.7%), the workload at the VAT (51.8±11.0 W vs. 52.9± 11.6 W), heart rate (HR) at the VAT (95.3±105 beats/min vs. 94.1±11.3 beats/min), or metabolic equivalent (METs) at the VAT (3.69±0.69 vs. 3.84±0.78) between the two sessions. The slope of linear regression for two repeated measurements was close to 1 (%VAT, 1.02; workload at the VAT, 0.95; METs at the VAT, 1.03), except for HR (0.70). Bland-Altman plots revealed the reproducibility of all four CPET measurements between the two sessions. In conclusion, CPET up to the VAT can be performed safely 1-day post-PCI in patients with stable CHD. CPET parameters do not significantly differ between testing performed the day after and 1-3 weeks after PCI. Next-day CPET during hospitalization after PCI may enable prompt exercise prescription without the need for another CPET 1-3 weeks later.

Cardiorespiratory fitness in early-stage breast cancer patients with radiotherapy-related fatigue: A prospective pilot study.

Leeman JE; Dana Farber Cancer Institute & Brigham and Women’s Hospital, Boston and Sloan Kettering Cancer Center, New York, NY.
Lapen K; Fuchs HE;Gonen Michalski M; Gillespie EF;Jones LW; McCormick B;

International journal of radiation oncology, biology, physics [Int J Radiat Oncol Biol Phys] 2023 Oct 30.
Date of Electronic Publication: 2023 Oct 30.

Purpose/objectives: Fatigue is among the most common but one of the most poorly understood radiotherapy-associated toxicities. This prospective study sought to investigate whether cardiorespiratory fitness, an integrative measure of whole-body cardiopulmonary function, is associated with patient-reported fatigue among women with early-stage breast cancer undergoing radiotherapy.
Materials/methods: Patients with stage Tis-T2N0M0 breast cancer and an ECOG performance status of 0-1 who were undergoing breast radiotherapy performed a symptom-limited cardiopulmonary exercise test (CPET) on a motorized treadmill to assess cardiorespiratory fitness (VO2 peak). Fatigue was assessed by the FACIT Fatigue Scale. Both assessments were performed during or immediately after radiotherapy completion. All patients were treated with an opposed tangent technique to a dose of 4240 cGy in 16 fractions with or without a lumpectomy bed boost. Patients receiving cytotoxic chemotherapy were excluded. Pearson’s correlation coefficients and univariate linear regression were used to assess associations between VO2 peak, fatigue, and patient characteristics.
Results: Twenty-eight patients (median age 52 years, range 31-71) completed both CPET and FACIT assessments. Median VO2 peak was 25.1 mL O2 . kg -1. min -1 (range 16.7-41.7). The majority of subjects (78.6%) displayed a VO 2 peak less than their age-predicted VO2 peak. Both age and BMI were significantly associated with VO2 peak levels. Median fatigue score was 41.5 (range 10-52), with lower values indicating more fatigue. VO2 peak was not associated with FACIT score (p=0.20).
Conclusions: Overall, VO2 peak was not a significant predictor of radiotherapy-related fatigue. Most breast cancer patients had marked impairments in cardiorespiratory fitness as determined by VO2 peak. Larger prospective studies are needed to further investigate this novel finding, and to evaluate the effects of interventions aimed at improving cardiorespiratory fitness and their ability to potentially prevent fatigue.

Validation of the maximal cardiopulmonary exercise test in adolescents with major depressive disorder and comparison of cardiorespiratory fitness with sex- and age-related control values.

Wenzel C; TU Dortmund University, Germany; and hospitals in Cologne, Dusseldorf, Stuggart and Maastricht
Bongers BC; Schlagheck ML; Reis D; IReinhard F; Schmidt P; Bernitzki S; Oberste M; Wunram HL;
Zimmer P; Fricke O;

European journal of pediatrics [Eur J Pediatr] 2023 Oct 31.
Date of Electronic Publication: 2023 Oct 31.

Endurance training has been shown to be effective in treating adolescents with major depressive disorder (MDD). To integrate endurance training into the therapeutic setting and the adolescents’ daily lives, the current performance status of the adolescents should be accurately assessed. This study aims to examine adolescents with MDD concerning exhaustion criteria during a cardiopulmonary exercise test (CPET), as well as to compare the values obtained thereon with sex- and age-related control values. The study included a retrospective examination of exhaustion criteria ((i) oxygen consumption (V̇O 2 ) plateau, (ii) peak respiratory exchange ratio (RER peak ) > 1.0, (iii) peak heart rate (HR peak ) ≥ 95% of the age-predicted maximal HR, and (iv) peak blood lactate concentration (BLC peak ) > 8.0 mmol⋅L -1 ) during a graded CPET on a cycle ergometer in adolescents with MDD (n = 57). Subsequently, maximal V̇O 2 , peak minute ventilation, V̇O 2 at the first ventilatory threshold, and peak work rate of participants who met at least two of four criteria were compared with published control values using an independent-sample t-test. Thirty-three percent of the total population achieved a V̇O 2 plateau and 75% a RER peak  > 1.0. The HR and BLC criteria were met by 19% and 22%, respectively. T-test results revealed significant differences between adolescents with MDD and control values for all outcomes. Adolescents with MDD achieved between 56% and 83% of control values.   Conclusions: The study shows that compared with control values, fewer adolescents with MDD achieve the exhaustion criteria on a CPET and adolescents with MDD have significantly lower cardiorespiratory fitness.
Clinical trial registration: No. U1111-1145-1854. What is Known: • It is already known that endurance training has a positive effect on depressive symptoms. What is New: • A relevant proportion of adolescents with major depressive disorder do not achieve their V̇O2max during a graded cardiopulmonary exercise test. • Adolescents with major depressive disorder have significantly lower cardiorespiratory fitness compared to sex- and age-related control values.

O2 pulse slope correlates with stroke volume during exercise in patients with a Fontan circulation.

Laohachai K; Sydney Medical School, Australia & and other hospitals in Australia
Cordina R; D’Udekem Y; Rice K; Weintraub R; Ayer J;

Open heart [Open Heart] 2023 Nov; Vol. 10 (2).

Background: Peak oxygen pulse (O2 pulse=oxygen consumption/heart rate) is calculated by the product of stroke volume (SV) and oxygen extraction. It has been shown to be reduced in patients with a Fontan circulation. However, in the Fontan population, it may be a poor marker of SV. We propose that the slope of the O2 pulse curve may be more reflective of SV during exercise.
Methods: We analysed cardiopulmonary exercise test data in 22 subjects with a Fontan circulation (cohort A) and examined the association between peak SV during exercise (aortic flow measured on exercise cardiac MRI), and O 2 pulse parameters (absolute O 2 pulse and O 2 pulse slopes up to anaerobic threshold (AT) and peak exercise). In a separate Fontan cohort (cohort B, n=131), associations between clinical characteristics and O 2 pulse kinetics were examined.
Results: In cohort A, peak aortic flow was moderately and significantly associated with O2 pulseslope PEAK (r=0.47, p=0.02). However, neither absolute O2 pulse AT nor O2 pulse PEAK was significantly associated with peak aortic flow. In cohort B, O2 pulseslope PEAK and O2 pulseslope AT were not significantly associated with clinical parameters, apart from a weak association with forced vital capacity.
Conclusion: The slope of the O2 pulse curve to peak exercise may be more reflective of peak SV in the Fontan population than a single peak O2 pulse value.

Impaired Cardiorespiratory Fitness and Endothelial Function After SARS-CoV-2 Infection in a Sample of Mainly Immunocompromised Youth.

Astley C; Children and Adolescent Institute: University of Sao Paulo, Sao Paulo, Brazil.
Prado DMLD; Sieczkowska SM; Esteves GP; Suguita P; Fink T; Lindoso L; Matsuo O; Martins F; Bain V; Badue MF; Marques HH; Malluf A; Leal G; Silva CA; Roschel H; Gualano B;

Journal of applied physiology (Bethesda, Md. : 1985) [J Appl Physiol (1985)] 2023 Nov 02.
Date of Electronic Publication: 2023 Nov 02.

Purpose: This study aimed to describe cardiopulmonary fitness and endothelial function 6 months after hospital diagnosis in a sample mainly comprising immunocompromised patients with confirmed SARS-Cov-2 infection vs. controls.
Methods: Youth (n=30; 14; 60% females) with confirmed SARS-CoV-2 seen in a tertiary hospital of Sao Paulo, Brazil, were matched by propensity score based on BMI, age, sex and pre-existing diseases with a control group who had not been tested positive for SARS-CoV-2 (n=30; age: 15; 50% females). Cardiopulmonary fitness (by means of a cardiopulmonary exercise test: CPET) and brachial flow-mediated dilation (%b-FMD) were assessed 6 months after diagnosis.
Results: Patients were similar for pre-existing diseases, sex, age and body mass index (all p>.05). Compared with controls, COVID-19 patients showed reduced VAT and peak exercise time (all p>.01), and VE/MVV (p<0.1). Brachial endothelial function variables were all adjust for body surface area (BSA). COVID-19 patients had decreased %b-FMD (3.6 vs. 5.4; p=.03) mean and positive flow (p=.02 and p=.03, respectively) vs. controls. Adjusted linear regression models exploring associations between CPET variables, %b-FMD and the potential predictors post-COVID-19 syndrome, number of symptoms, hospitalization and COVID severity did not detect significant associations, except for total shear rate in hospitalization (Coefficient: -65.07 [95%CI -119.5;-10.5], p=0.02).
Conclusion: In a sample of mainly immunocompromised youth with COVID-19, we found impaired exercise performance and endothelial function. These findings reinforce the need for preventive measures against infection in this vulnerable population and suggest that proper monitoring and treatment for these patients are warranted.

Pulmonary vasodilators and exercise in Fontan circulation: a systematic review and meta-analysis.

Kosmidis D; AHEPA University Hospital,  Thessaloniki, Greece.
Arvanitaki A; Farmakis IT; Liakos A; Giannopoulos A; Ziakas A; First Giannakoulas G;

Heart (British Cardiac Society) [Heart] 2023 Nov 02.
Date of Electronic Publication: 2023 Nov 02.

Objective: In Fontan circulation, pulmonary arterial hypertension (PAH)-targeted therapies could improve the patients’ exercise capacity. This study aimed to investigate the effects of PAH agents on different exercise parameters in stable Fontan patients by synthesising evidence of randomised controlled trials (RCTs).
Methods: A systematic search of PubMed, Cochrane Central Register of Controlled Trials and Web of Science databases, as well as of ClinicalTrials.gov, was performed. Primary outcomes were specific cardiopulmonary exercise test parameters: peak oxygen uptake (peak VO 2 ), peak heart rate (peak HR), the minute ventilation/produced carbon dioxide (VE/VCO 2 ) slope and the oxygen uptake, both measured at the anaerobic threshold (VO 2 @AT).
Results: Five RCTs were included in the analysis including 573 Fontan patients (mean age 21.2 years, 60% male). PAH-targeted therapies did not affect peak VO 2 (mean difference (MD) 0.72, 95% CI -0.25 to 1.70) or peak HR (MD -0.67, 95% CI -3.81 to 2.47), but resulted in a small, significant improvement in VO 2 @AT (standardised MD 0.24, 95% CI 0.02 to 0.47). VE/VCO 2 slope at the anaerobic threshold was also reduced (MD -1.13, 95% CI -2.25 to -0.01).
Conclusions: Although PAH-targeted therapies did not affect exercise parameters at maximal effort, they induced slight improvements in indices of submaximal effort, measured at the anaerobic threshold. Pharmacological improvement of submaximal exercise seems to be a more suitable indicator of Fontan individuals’ exercise capacity. Larger RCTs, recruiting specific subpopulations and focusing also on the anaerobic threshold, are warranted to draw more robust conclusions.