Chest
Volume 105, Issue 1, January 1994, Pages 168-174
Journal home page for Chest

Clinical Investigations: Exercise
Graded Comprehensive Cardiopulmonary Exercise Testing in the Evaluation of Dyspnea Unexplained by Routine Evaluation

https://doi.org/10.1378/chest.105.1.168Get rights and content

The evaluation of dyspnea is problematic when a cause is inapparent after initial diagnostic studies. We examined the results and role of cardiopulmonary exercise testing (CPET) in 50 patients with a mean 23 months of dyspnea and normal FEV1 and FVC. The CPET studies were interpreted by a panel and a consensus reached. Subsequent tests ordered by the primary physician were reviewed, and a final diagnosis was agreed on by the panel. Seven of 50 patients had cardiac limitation, 17 of 50 had pulmonary limitation, 14 of 50 had obesity and/or deconditioning, 1 of 50 had gastroesophageal reflux, and 16 of 50 had either psychogenic dyspnea or no identifiable disease. Five patients had more than one clinical diagnosis accounting for 55 diagnoses in the 50 patients. Those with a normal CPET had a higher Vo2max and O2 pulse than those with cardiac disease, deconditioning, or hyperactive airways disease (HAD) (p < 0.05). Electrocardiographic changes identified cardiac disease while studies demonstrating ventilatory limitation identified a pulmonary process. In 24, deconditioning could not be distinguished from cardiac limitation. Of these, 14 responded to exercise training and/or weight loss, whereas 3 had cardiac disease, 7 had HAD, and 4 had psychogenic dyspnea (4 had more than one clinical diagnosis). In the 13 patients with normal CPET results, one had gastroesophageal reflux, two had HAD, four had psychogenic dyspnea, and six had no identifiable disease. We conclude that a diagnosis can be made in most patients with chronic dyspnea; however, further studies including bronchoprovocation are often required. Cardiopulmonary exercise testing is useful in identifying a cardiac or pulmonary process, but it is insensitive in distinguishing cardiac disease from deconditioning.

Section snippets

Patient Population

Patients were entered after fulfilling the following criteria: (1) a presenting complaint of dyspnea on exertion; (2) history, physical examination, routine blood studies (complete blood cell count, serum chemistries, thyroid function tests), chest radiograph (CXR) that did not provide an adequate explanation of the complaint; (3) normal flow-volume loop; (4) FEV1 >80 percent predicted, FVC >80 percent predicted, and FEV1/FVC >70 percent; and (5) the ability to complete an adequate

Results

The clinical characteristics and spirometry of the 50 patients are presented in Table 2. The 23 male and 27 female patients had a median duration of symptoms of 23 months (range, 3 to 240 months). The FEV1 and FVC were normal; the median Dco approached a normal value. The median duration of follow-up was 9.1 months (range, 2.5 to 80 months). In those patients with early resolution of symptoms after appropriate therapy, the follow-up was shorter. On review of the initial 14 CPET interpretations,

Discussion

The physiologic basis of dyspnea is a topic of which much has been written.1, 2 Much less has been written regarding the clinical evaluation of the patient presenting with this complaint.3, 4, 5 To our knowledge, no previous study has specifically examined CPET in the evaluation of chronic, unexplained dyspnea. We show that a diagnostic CPET study serves to identify cardiac and pulmonary disease in patients presenting with dyspnea who have no obvious cause after initial testing. Normal results

References (43)

  • EliassonA.H. et al.

    Sensitivity and specificity of bronchial provocation testing: an evaluation of four techniques in exercise-induced bronehospasm

    Chest

    (1992)
  • MohsenifarZ. et al.

    Isolated reduction in single-breath diffusing capacity in the evaluation of exertional dyspnea

    Chest

    (1992)
  • FishJ.E. et al.

    Measurement of responsiveness in bronchoprovocation testing

    J Allergy Clin Immunol

    (1979)
  • EgglestonP.A. et al.

    A standardized method of evaluating exercise induced asthma

    J Allergy Clin Immunol

    (1976)
  • LeblancP. et al.

    Breathlessness and exercise in patients with cardiorespiratory disease

    Am Rev Respir Dis

    (1986)
  • TobinM.J.

    Dyspnea. Pathophysiologic basis, clinical presentation, and management

    Arch Intern Med

    (1990)
  • PratterM.R. et al.

    Cause and evaluation of chronic dyspnea in a pulmonary disease clinic

    Arch Intern Med

    (1989)
  • NeatonJ.D. et al.

    Serum cholesterol, blood pressure, cigarette smoking and death from coronary heart disease: overall findings and differences by age for 316,099 white men

    Arch Intern Med

    (1992)
  • WassermanK. et al.

    Principles of exercise testing and interpretation

    (1987)
  • American Thoracic Society

    Standardization of spirometry= m1987 update: ATS statement

    Am Rev Respir Dis

    (1987)
  • CherniackR.M. et al.

    Normal standards for ventilatory function using an automated wedge spirometer

    Am Rev Respir Dis

    (1972)
  • Cited by (103)

    • Iron Deficiency Is Associated With Impaired Biventricular Reserve and Reduced Exercise Capacity in Patients With Unexplained Dyspnea

      2021, Journal of Cardiac Failure
      Citation Excerpt :

      Dyspnea is a common presenting symptom in clinical practice. Community population studies highlight the prevalence of dyspnea between 9% and 13%, and ≤25% in patients seeking medical care in a primary health care setting.1–5 This number further increases up to 50% when patients are admitted to the hospital.

    • Incorporating Lung Diffusing Capacity for Carbon Monoxide in Clinical Decision Making in Chest Medicine

      2019, Clinics in Chest Medicine
      Citation Excerpt :

      Key recommendations for the clinical interpretation of Dlco in different scenarios are shown in Table 2. Chronic dyspnea despite normal spirometry, chest radiograph, and resting echocardiogram is a frequent and challenging scenario in the chest physician’s office (further discussion the topic is provided in Unraveling the Causes of Unexplained Dyspnea: The Value of Exercise Testing).39–41 Preserved Dlco might be reassuring that major respiratory disease is not present,13 particularly if associated with normal static lung volumes.

    View all citing articles on Scopus

    Supported by funds from the National Institutes of Health NHLBI grant P50HL46487 and the NCRR grant M01RR00042-3353.

    View full text