Cardiopulmonary testing in long COVID-19 versus non-COVID-19 patients with undifferentiated Dyspnea on exertion

Abstract:

Background: Dyspnea and fatigue are characteristics of long SARS-CoV-2 (COVID)-19. Cardiopulmonary exercise testing (CPET) can be used to better evaluate such patients.

Research question: How significantly and by what mechanisms is exercise capacity impaired in patients with long COVID who are coming to a specialized clinic for evaluation?

Study design and methods: We performed a cohort study using the Mayo Clinic exercise testing database. Subjects included consecutive long COVID patients without prior history of heart or lung disease sent from the Post-COVID Care Clinic for CPET. They were compared to a historical group of non-COVID patients with undifferentiated dyspnea also without known cardiac or pulmonary disease. Statistical comparisons were performed by t-test or Pearson’s chi2 test controlling for age, sex, and beta blocker use where appropriate.

Results: We found 77 patients with long COVID and 766 control patients. Long COVID patients were younger (47 ± 15 vs 50 ± 10 years, P < .01) and more likely female (70% vs 58%, P < .01). The most prominent difference on CPETs was lower percent predicted peak V̇O2 (73 ± 18 vs 85 ± 23%, p < .0001). Autonomic abnormalities (resting tachycardia, CNS changes, low systolic blood pressure) were seen during CPET more commonly in long COVID patients (34 vs 23%, P < .04), while mild pulmonary abnormalities (mild desaturation, limited breathing reserve, elevated V̇E/V̇CO2) during CPET were similar (19% in both groups) with only 1 long COVID patient showing severe impairment.

Interpretation: We identified severe exercise limitation among long COVID patients. Young women may be at higher risk for these complications. Though mild pulmonary and autonomic impairment were common in long COVID patients, marked limitations were uncommon. We hope our observations help to untangle the physiologic abnormalities responsible for the symptomatology of long COVID.

Source: Contreras AM, Newman DB, Cappelloni L, Niven AS, Mueller MR, Ganesh R, Squires RW, Bonikowske AR, Allison TG. Cardiopulmonary testing in long COVID-19 versus non-COVID-19 patients with undifferentiated Dyspnea on exertion. Prog Cardiovasc Dis. 2023 May 19:S0033-0620(23)00053-1. doi: 10.1016/j.pcad.2023.05.005. Epub ahead of print. PMID: 37211198; PMCID: PMC10198738. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10198738/ (Full text)

Use of Cardiopulmonary Stress Testing for Patients With Unexplained Dyspnea Post-Coronavirus Disease

Abstract:

Objectives: The authors used cardiopulmonary exercise testing (CPET) to define unexplained dyspnea in patients with post-acute sequelae of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection (PASC). We assessed participants for criteria to diagnose myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Background: Approximately 20% of patients who recover from coronavirus disease (COVID) remain symptomatic. This syndrome is named PASC. Its etiology is unclear. Dyspnea is a frequent symptom.

Methods: The authors performed CPET and symptom assessment for ME/CFS in 41 patients with PASC 8.9 ± 3.3 months after COVID. All patients had normal pulmonary function tests, chest X-ray, and chest computed tomography scans. Peak oxygen consumption (peak VO2), slope of minute ventilation to CO2 production (VE/VCO2 slope), and end tidal pressure of CO2 (PetCO2) were measured. Ventilatory patterns were reviewed with dysfunctional breathing defined as rapid erratic breathing.

Results: Eighteen men and 23 women (average age: 45 ± 13 years) were studied. Left ventricular ejection fraction was 59% ± 9%. Peak VO2 averaged 20.3 ± 7 mL/kg/min (77% ± 21% predicted VO2). VE/VCO2 slope was 30 ± 7. PetCO2 at rest was 33.5 ± 4.5 mm Hg. Twenty-four patients (58.5%) had a peak VO2 <80% predicted. All patients with peak VO2 <80% had a circulatory limitation to exercise. Fifteen of 17 patients with normal peak VO2 had ventilatory abnormalities including peak respiratory rate >55 (n = 3) or dysfunctional breathing (n = 12). For the whole cohort, 88% of patients (n = 36) had ventilatory abnormalities with dysfunctional breathing (n = 26), increased VE/VCO2 (n = 17), and/or hypocapnia PetCO2 <35 (n = 25). Nineteen patients (46%) met criteria for ME/CFS.

Conclusions: Circulatory impairment, abnormal ventilatory pattern, and ME/CFS are common in patients with PASC. The dysfunctional breathing, resting hypocapnia, and ME/CFS may contribute to symptoms. CPET is a valuable tool to assess these patients.

Source: Mancini DM, Brunjes DL, Lala A, Trivieri MG, Contreras JP, Natelson BH. Use of Cardiopulmonary Stress Testing for Patients With Unexplained Dyspnea Post-Coronavirus Disease. JACC Heart Fail. 2021 Dec;9(12):927-937. doi: 10.1016/j.jchf.2021.10.002. PMID: 34857177.  https://pubmed.ncbi.nlm.nih.gov/34857177/

Atrial myxoma: a rare cause of progressive exertional dyspnoea

Abstract:

A 40 year old man suffered eight years of vague but disabling symptoms, initially thought to be related to post viral fatigue syndrome, but ameliorated by the removal of a large atrial myxoma. The diagnosis of atrial myxoma is notoriously difficult, but should be excluded by echocardiography if there are predominant symptoms of progressive exertional dyspnoea, even in the absence of cardiological signs.

 

Source: Gray JB, Bridges AB, McNeill GP. Atrial myxoma: a rare cause of progressive exertional dyspnoea. Scott Med J. 1992 Dec;37(6):186-7. http://www.ncbi.nlm.nih.gov/pubmed/1492217