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Cited by 113Long-Term Effects of COVID-19Cardiovascular and exercise physiologyCOVID-19 Clinical Research Studies

Dysfunctional breathing diagnosed by cardiopulmonary exercise testing in 'long COVID' patients with persistent dyspnoea

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Frésard, Isabelle, Genecand, Léon, Altarelli, Marco, Gex, Grégoire, Vremaroiu, Petrut, Vremaroiu-Coman, Andreea, Lawi, David, Bridevaux, Pierre-Olivier·2022·BMJ Open Respiratory Research
DOI 10.1136/bmjresp-2021-001126PMC PMC8968537
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Abstract

Background: ‘Long COVID’-associated dyspnoea may persist for months after SARS-CoV-2 infection. Among the causes of persistent dyspnoea, dysfunctional breathing (DB), defined as an erratic or inappropriate ventilation at rest or exercise, has been observed, but little is known about its occurrence and pathophysiology among individuals with ‘long COVID’. We aimed to describe the occurrence and identify clinical predictors of DB among patients following SARS-CoV-2 infection. Methods: Cardiopulmonary exercise testing (CPET) was performed in 51 SARS-CoV-2 patients (median age, 64 years (IQR, 15)); male, 66.7%) living with ‘long COVID’ and persistent dyspnoea. CPET was classified into three dominant patterns: respiratory limitation with gas exchange abnormalities (RL); normal CPET or O 2 delivery/utilisation impairment (D); and DB. Non-parametric and χ 2 tests were applied to analyse the association between CPET dominant patterns and demographics, pulmonary function tests and SARS-CoV-2 severity. Results: Among 51 patients, DB mostly without hyperventilation was found in 29.4% (n=15), RL in 54.9% (n=28) and D in 15.7% (n=8). When compared with RL individuals, patients with DB were younger, had significantly less severe initial infection, a better transfer capacity for carbon monoxide (median 85% (IQR, 28)), higher oxygen consumption (22.9 mL/min/kg (IQR, 5.5)), a better ventilatory efficiency slope (31.6 (IQR, 12.8)), and a higher SpO 2 (95% (IQR, 3)). Conclusions: Our findings suggest that DB without hyperventilation could be an important pathophysiological mechanism of disabling dyspnoea in younger outpatients following SARS-CoV-2 infection, which appears to be a feature of COVID-19 not described in other viral diseases.

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  • Hancox et al. reported wheeze as a cardinal feature of asthma which is not regarded as a DB symptom.

    “Hancox et al. reported wheeze as a cardinal feature of asthma which is not regarded as a DB symptom (42).”

    From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [42]

    The Discussion describes dysfunctional breathing in these long-COVID patients as erratic breathing with deep sighs, but does not address whether wheeze is an asthma feature or a dysfunctional-breathing symptom. Searches for “Hancox” and “wheeze” found no passage supporting the attributed statement; the copy does not establish what Hancox et al. reported. (LLM, conf=0.76)

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Research works printed but not linked: 25

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Cited by

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Authors
Frésard, I., Genecand, L., Altarelli, M., Gex, G., Vremaroiu, P., Vremaroiu-Coman, A., Lawi, D., & Bridevaux, P.-O.
Affiliations
  • Hôpital Riviera-Chablais (CH)
  • University of Geneva (CH)
  • Hôpital de Sion (CH)
Corresponding author
Frésard, Isabelle
ORCID
Venue
BMJ Open Respiratory Research
Publisher
BMJ
Published
2022-03
Volume
9
Issue
1
Pages
e001126
ISSN
2052-4439 (ISSN-L)
DOI
10.1136/bmjresp-2021-001126
PMC
PMC8968537
OpenAlex
W4220655341
Cited by
113
References
1
Citations by year
2026: 10 · 2025: 19 · 2024: 31 · 2023: 35 · 2022: 18
FWCI
13.56
Type
journal article
Language
en
Open access
Licence
Locations
  • BMJ Open Respiratory Research (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • Archive ouverte UNIGE (University of Geneva) (submittedVersion, cc-by-nc)
Topics
  • Health Sciences › Medicine › Neurology › Long-Term Effects of COVID-19
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
Keywords
long COVID, dysfunctional breathing, COVID-19 pandemic, cardiopulmonary exercise testing, ventilatory efficiency, oxygen consumption, hyperventilation, COVID-19 severity, lung function
MeSH terms
COVID-19, SARS-CoV-2, Post-Acute COVID-19 Syndrome, Dyspnea, Exercise Test, Humans, Male, Middle Aged, Respiration, Exercise Tolerance

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