Category Archives: Abstracts

Wong, M; Asthma, Allergy and Clinical Immunology Service, Alfred Health, Australia.
Gardner, L; Denton, E, et al.

Journal of science and medicine in sport,2025 Feb

Objectives: Abnormal breathlessness at maximal exercise may be caused by a range of conditions, including exercise-induced bronchospasm, breathing pattern disorder, or exercise-induced laryngeal obstruction. These three disorders may not be detected on standard cardiopulmonary exercise testing. The aim of this study was to describe diagnostic outcomes of an expanded protocol during cardiopulmonary exercise testing.
Design: Retrospective cohort study.
Methods: Patients presenting with abnormal breathlessness on maximal exercise underwent continuous laryngoscopy with cardiopulmonary exercise testing on a stationary cycle ergometer. Breathing pattern disorder was evaluated by video and ventilatory data. Pre- and post-exercise spirometry was performed.
Results: 24 adult patients were evaluated; 10 were professional athletes. Mean age was 40 years (range 18-73). Nine of 24 (38 %) were diagnosed with exercise-induced laryngeal obstruction and referred for speech pathology. Six of these had supraglottic exercise-induced laryngeal obstruction; all were aged <30 years; 5/6 were professional athletes. One patient had breathing pattern disorder and was referred for physiotherapy; one had exercise-induced bronchospasm, requiring escalation of asthma medication; one had muscle tension dysphonia resulting in referral to an otolaryngologist who administered a laryngeal injection of botulinum toxin. A further four patients had unexplained lower maximal oxygen consumption with cardiac limitation and were referred for further cardiac investigation.
Conclusions: In patients reporting abnormal breathlessness at maximal exercise, this expanded exercise protocol provided diagnostic information in 66.7 % cases which contributed to further personalised management.

Dyspnea in young subjects with congenital central hypoventilation syndrome.

February 17, 2025

Bokov, P; Hôpital Robert Debré, Service de Physiologie Pédiatrique, Paris, France
Dudoignon, B; Fikiri Bavurhe; R;Couque, N; et al

Pediatric research,2025 Jan

Background: It has been stated that patients with congenital central hypoventilation syndrome (CCHS) do not perceive dyspnea, which could be related to defective CO ₂ chemosensitivity.
Methods: We retrospectively selected the data of six-minute walk tests (6-MWT, n = 30), cardiopulmonary exercise test (CPET, n = 5) of 30 subjects with CCHS (median age, 9.3 years, 17 females) who had both peripheral (controller loop gain, CG0) and central CO ₂ chemosensitivity (hyperoxic, hypercapnic response test [HHRT]) measurement.
Main Results: Ten subjects had no symptom during the HHRT, as compared to the 20 subjects exhibiting symptoms, their median ages were 14.7 versus 8.8 years (p = 0.006), their maximal PETCO ₂ were 71.6 versus 66.7 mmHg (p = 0.007), their median CO ₂ response slopes were 0.28 versus 0.30 L/min/mmHg (p = 0.533) and their CG0 values were 0.75 versus 0.50 L/min/mmHg (p = 0.567). Median dyspnea Borg score at the end of the 6-MWT was 1/10 (17/30 subjects >0), while at the end of the CPET it was 3/10 (sensation: effort). This Borg score positively correlated with arterial desaturation at walk (R = 0.43; p = 0.016) and did not independently correlate with CO ₂ chemosensitivities.
Conclusion: About half of young subjects with CCHS do exhibit mild dyspnea at walk, which is not related to hypercapnia or residual CO ₂ chemosensitivity.
Impact: Young subjects with CCHS exhibit some degree of dyspnea under CO ₂ exposure and on exercise that is not related to residual CO ₂ chemosensitivity. It has been stated that patients with CCHS do not perceive sensations of dyspnea, which must be tempered. The mild degree of exertional dyspnea can serve as an indicator for the necessity of breaks.

Cardiopulmonary Exercise Testing With Simultaneous Echocardiography After Pulmonary Embolism.

February 17, 2025

Khilzi, Pulmonology Department-Hospital del Mar Pulmonary Hypertension Unit Barcelona Spain.
Karys; Piccari, Lucilla; Franco, Gerard, et al.

Pulmonary circulation,2025 Feb 05Although current guidelines recommend standard cardiopulmonary exercise testing (CPET) to evaluate symptomatic patients after pulmonary embolism (PE), CPET with simultaneous echocardiography could provide relevant information to evaluate right ventricular-pulmonary arterial coupling.
AIMS
The aim of this study was to investigate exercise-induced changes in echocardiographic variables of RV function or RV- arterial coupling in patients with residual thrombotic defects at 3 months after PE.
METHODS
This retrospective study investigated patients with residual thromboembolic disease on V/Q scintigraphy with persistent symptoms despite adequate anticoagulation after 3 months of acute PE, and resting echocardiography with a low probability of PH. At rest and during exercise, CPET and doppler echocardiography were performed following a standard protocol. Forty-five patients were included, completing a follow-up period of at least 24 months. The mean (standard deviation) age was 63 (15) years, and 24 (53%) patients were male.
RESULTS
Four patients developed CTEPH after 2 years follow up. Correlation analyses showed that the peak TAPSE was significantly associated with peak workload ( r = 0.454, p = 0.003), peak VO ₂ ( r = 0.558, p < 0.001), VE/VECO ₂ (AT) ( r = -0.531, p < 0.001), and oxygen pulse ( r = 0.375, p = 0.02). TAPSE/PASP was only slightly associated with peak workload ( r = 0.300, p = 0.045). By contrast, the change on TAPSE (from rest to peak) was significantly correlate with peak oxygen uptake ( r = 0.491, p = 0.01). Also, reduced VO ₂ at AT and TAPSE/PASP was seen in patients with CTEPH. CPET with synchronic echocardiography could be a useful tool in early assessment of symptomatic patients with perfusion defects on imaging after 3 months of correctly treated PE.

Acute oral digoxin in healthy adults hastens fatigue and increases plasma K(+) during intense exercise, despite preserved skeletal muscle Na(+),K(+)-ATPase

February 10, 2025

T. Atanasovska, Melbourne Australia
T. Farr, R. Smith, A. C. Petersen, A. Garnham, M. J. Andersen, et al.

J Physiol 2024 Vol. 602 Issue 24 Pages 6849-6869

We investigated acute effects of the Na(+),K(+)-ATPase (NKA) inhibitor, digoxin, on muscle NKA content and isoforms, arterial plasma [K(+)] ([K(+)](a)) and fatigue with intense exercise.
In a randomised, crossover, double-blind design, 10 healthy adults ingested 0.50 mg digoxin (DIG) or placebo (CON) 60 min before cycling for 1 min at 60% V̇O2peak then at 95% V̇O2peak until fatigue. Pre- and post-exercise muscle biopsies were analysed for [(3)H]-ouabain binding site content without (OB-F(ab)) and after incubation in digoxin antibody (OB+F(ab)) and NKA alpha(1-2) and beta(1-2) isoform proteins. In DIG, pre-exercise serum [digoxin] reached 3.36 (0.80) nM [mean (SD)] and muscle NKA-digoxin occupancy was 8.2%. Muscle OB-F(ab) did not differ between trials, whereas OB+F(ab) was higher in DIG than CON (8.1%, treatment main effect, P = 0.001), whilst muscle NKA alpha(1-2) and beta(1-2) abundances were unchanged by digoxin. Fatigue occurred earlier in DIG than CON [-7.7%, 2.90 (0.77) vs. 3.14 (0.86) min, respectively; P = 0.037]. [K(+)](a) increased during exercise until 1 min post-exercise (P = 0.001), and fell below baseline at 3-10 (P = 0.001) and 20 min post-exercise (P = 0.022, time main effect). In DIG, [K(+)](a) (P = 0.035, treatment effect) and [K(+)](a) rise pre-fatigue were greater [1.64 (0.73) vs. 1.55 (0.73), P = 0.016], with lesser post-exercise [K(+)](a) decline than CON [-2.55 (0.71) vs. -2.74 (0.62) mM, respectively, P = 0.003]. Preserved muscle OB-F(ab) with digoxin, yet increased OB+F(ab) with unchanged NKA isoforms, suggests a rapid regulatory assembly of existing NKA alpha and beta subunits exists to preserve muscle NKA capacity. Nonetheless, functional protection against digoxin was incomplete, with earlier fatigue and perturbed [K(+)](a) with exercise.
KEY POINTS: Intense exercise causes marked potassium (K(+)) shifts out of contracting muscle cells, which may contribute to muscle fatigue. Muscle and systemic K(+) perturbations with exercise are largely regulated by increased activity of Na(+),K(+)-ATPase in muscle, which can be specifically inhibited by the cardiac glycoside, digoxin. We found that acute oral digoxin in healthy adults reduced time to fatigue during intense exercise, elevated the rise in arterial plasma K(+) concentration during exercise and slowed K(+) concentration decline post-exercise. Muscle functional Na(+),K(+)-ATPase content was not reduced by acute digoxin, despite an 8.2% digoxin occupancy, and was unchanged at fatigue. Muscle Na(+),K(+)-ATPase isoform protein abundances were unchanged by digoxin or fatigue. These suggest possible rapid assembly of existing subunits into functional pumps. Thus, acute digoxin impaired performance and exacerbated plasma K(+) disturbances with intense, fatiguing exercise in healthy participants. These occurred despite the preservation of functional Na(+),K(+)-ATPase in muscle.

Clinical Tools to Assess Functional Capacity During Risk Assessment Before Elective Noncardiac Surgery : A Scoping Review. [Review]

Daza JF; University of Toronto, Toronto, Ontario, Canada
Chesney TR; Morales JF; Xue Y; Lee S; Amado LA; Pivetta B;
Mbadjeu Hondjeu AR; Jolley R; Diep C; Alibhai SMH; Smith PM; Kennedy ED;
Racz E; Wilmshurst L; Wijeysundera DN

Annals of Internal Medicine. 178(1):75-87, 2025 Jan.

BACKGROUND: Functional capacity is critical to preoperative risk
assessment, yet guidance on its measurement in clinical practice remains
lacking.
PURPOSE: To identify functional capacity assessment tools studied before
surgery and characterize the extent of evidence regarding performance,
including in populations where assessment is confounded by
noncardiopulmonary reasons.
DATA SOURCES: MEDLINE, EMBASE, and EBM Reviews (until July 2024).
STUDY SELECTION: Studies evaluating performance of functional capacity
assessment tools administered before elective noncardiac surgery to
stratify risk for postoperative outcomes.
DATA EXTRACTION: Study details, measurement properties, pragmatic
qualities, and/or clinical utility metrics.
DATA SYNTHESIS: 6 categories of performance-based tests and 5 approaches
using patient-reported exercise tolerance were identified. Cardiopulmonary
exercise testing (CPET) was the most studied tool (132 studies, 32 662
patients) followed by field walking tests (58 studies, 9393 patients)
among performance-based tests. Among patient-reported assessments, the
Duke Activity Status Index (14 studies, 3303 patients) and unstructured
assessments (19 studies, 28 520 patients) were most researched. Most
evidence focused on predictive validity (92% of studies), specifically
accuracy in predicting cardiorespiratory complications. Several tools
lacked evidence on reliability (test consistency across similar
measurements), pragmatic qualities (feasibility of implementation), or
concurrent criterion validity (correlation to gold standard). Only CPET
had evidence on clinical utility (whether administration improved
postoperative outcomes). Older adults (>=65 years) were well represented
across studies, whereas there were minimal data in patients with obesity,
lower-limb arthritis, and disability.
LIMITATION: Synthesis focused on reported data without requesting missing
information.
CONCLUSION: Though several tools for preoperative functional capacity
assessment have been studied, research has overwhelmingly focused on CPET
and only 1 aspect of validity (predictive validity). Important evidence
gaps remain among vulnerable populations with obesity, arthritis, and
physical disability.

Hemodynamic responses at anaerobic threshold during exercise in preload insufficiency.

Fakhri S; Boston University Medical Center, Boston, Massachusetts, USA.
Campedelli L; Risbano MG

European Journal of Clinical Investigation. 55(2):e14343, 2025 Feb.

BACKGROUND: Preload insufficiency is an underrecognized cause of exercise
intolerance identified during invasive cardiopulmonary exercise testing,
and defined hemodynamically by decreased biatrial filling pressures,
cardiac output, and oxygen consumption (VO2) at peak effort. Patients with
preload insufficiency, however, typically present with symptoms of dyspnea
on exertion, and/or exercise intolerance at submaximal efforts,
particularly when performing activities of daily living. The
cardiopulmonary hemodynamics and physiology at submaximal work levels of
preload insufficiency have not been previously investigated. We
hypothesized that preload insufficiency hemodynamics exist along a
continuum, with submaximal exercise values reflecting peak exercise
cardiopulmonary hemodynamics.
METHODS: We compared submaximal cardiopulmonary hemodynamics, measured at
anaerobic threshold, between preload insufficiency patients and
age-matched controls referred for dyspnea but with normal exercise
responses.
RESULTS: Our study included 66 patients: 41 with preload insufficiency
and 25 controls. Preload insufficiency patients exhibit significantly
reduced VO2, watts, and METS at submaximal levels compared to controls,
alongside earlier anaerobic threshold achievement and similar heart rates
at anaerobic threshold.
CONCLUSIONS: These findings underscore the profound impact of preload
insufficiency on submaximal exercise capacity, emphasizing the importance
of its recognition and management. This insight sets the stage for further
investigations into interventions targeting preload insufficiency at
submaximal exercise levels to enhance both exercise performance and
quality of life.

Systolic blood pressure response during exercise testing in symptomatic severe aortic stenosis.

Nilsson H; Linkoping University, Linkoping,Sweden
Bellander C; Carlen A; Nylander E; Hedman K; Tamas E

Open Heart. 12(1), 2025 Jan 21.
VI 1

AIMS: Exercise testing remains underused in patients with aortic stenosis
(AS), partly due to concerns about an exercise-induced drop in systolic
blood pressure (SBP). We aimed to study the SBP response to exercise in
patients with severe symptomatic AS prior to surgery and 1 year
postoperatively.

METHODS: Patients scheduled for aortic valve replacement due to severe
symptomatic AS were enrolled at a single centre in a prospective
observational cohort study. Maximal cardiopulmonary exercise testing
(CPET) was performed on a cycle ergometer at baseline and 1 year
postoperatively, using standard termination criteria. The SBP response was
categorised according to the last measurements of SBP during exercise, in
relation to workload (the SBP/watt-slope) as ‘normal’ (>0.25 mm Hg/watt),
‘flat’ (0-0.25 mm Hg/watt) or ‘drop’ (<0 mm Hg/watt).

RESULTS: 45 patients (28 male, 66+/-9 years, left ventricular ejection
fraction 59%+/-5%, aortic jet velocity 4.6+/-0.5 m/s) were included, with
pairwise comparison available in 31 cases. There were no adverse events.
Preoperatively, 4/45 patients were categorised as ‘drop’, 23 as ‘flat’ and
18 as ‘normal’. There was a change in the distribution of categories from
preoperative to postoperative measurements (43% ‘normal’ vs 74% ‘normal’,
p=0.0046). Maximal SBP and workload-indexed SBP were higher
postoperatively than preoperatively (203+/-26 vs 182+/-28 mm Hg, p<0.001
and 0.43+/-0.14 vs 0.29+/-0.15 mm Hg/watt, p<0.001).

CONCLUSION: As a drop in SBP was infrequent (<10%) in patients with
severe symptomatic AS and no adverse events occurred, our results indicate
that CPET may be performed under careful monitoring in AS patients.
Postoperatively, the SBP reaction improved, with no patient having a drop
in SBP.

Recovery of heart rate and heart rate variability after a maximal cardiopulmonary exercise test in novice female runners.

Kaikkonen, Piia; UKK Institute, Kaupinpuistonkatu 1, 33500, Tampere, Finland
Pasanen, Kati; Parkkari, Jari;Mustakoski, Iida; Vasankari, Tommi; Leppänen, Mari

European Journal of Applied Physiology (EUR J APPL PHYSIOL), Jan2025; 125(1): 71-79. (9p)

No abstract available

Surviving Critical Care: A Follow-Up Study Assessing Pulmonary Function, Cardiopulmonary Exercise Testing, and Quality of Life in COVID-19-Affected Patients.