What is the workup for non-cardiac exertional dyspnea (shortness of breath on exertion not related to heart disease)?

From the Guidelines

The workup for non-cardiac exertional dyspnea should begin with a chest radiograph as the initial imaging study, as it can reveal a wide variety of abnormalities that may guide further imaging choices. This approach is supported by the American College of Radiology Appropriateness Criteria, which recommends chest radiography as the initial imaging study in chronic dyspnea of non-cardiovascular origin 1.

Initial Evaluation

The initial evaluation of non-cardiac exertional dyspnea should include:

• A thorough history and physical examination to identify potential causes of dyspnea
• Basic testing, including complete blood count, comprehensive metabolic panel, and chest X-ray
• Pulmonary function tests (PFTs) to evaluate for obstructive lung diseases like asthma or COPD, and restrictive disorders

Further Testing

Further testing may include:

• Spirometry with bronchodilator response, lung volumes, and diffusion capacity to evaluate pulmonary function
• Exercise testing, such as the 6-minute walk test or cardiopulmonary exercise testing, to quantify functional limitations and identify the primary cause of dyspnea
• High-resolution chest CT to evaluate for interstitial lung disease
• Methacholine challenge for suspected asthma when spirometry is normal
• Arterial blood gases to assess for hypoxemia or acid-base disturbances

Specialized Testing

Specialized testing may be necessary to evaluate for specific causes of dyspnea, such as:

• Pulmonary embolism, which should be considered in patients with risk factors and evaluated with D-dimer testing and CT pulmonary angiography if indicated
• Vocal cord dysfunction, which may require laryngoscopy during symptoms
• Anemia, which should be ruled out with hemoglobin testing

Consultation

Early consultation with a pulmonologist is recommended if the diagnosis remains unclear after initial testing or if specialized testing is needed for definitive diagnosis. This systematic approach can help identify common causes of non-cardiac dyspnea, including pulmonary disorders, deconditioning, obesity, anemia, and neuromuscular weakness 1.

From the Research

Non-Cardiac Exertional Dyspnea Workup

• The workup for non-cardiac exertional dyspnea typically begins with a detailed history and physical examination to identify potential causes 2, 3, 4, 5, 6
• Initial testing may include:
  • Complete blood count
  • Basic chemistry panel
  • Electrocardiography
  • Chest radiography
  • Spirometry
  • Pulse oximetry 2, 4, 6
• If no cause is identified, second-line noninvasive testing may be suggested, including:
  • Echocardiography
  • Cardiac stress tests
  • Pulmonary function tests
  • Computed tomography scan of the lungs 2, 4, 6
• Additional tests that may be required to diagnose underlying pathology include:
  • Cardiopulmonary exercise testing
  • Methacholine challenge
  • Ventilation perfusion scans
  • Holter monitoring
  • Cardiac catheterization
  • Esophageal pH monitoring
  • Lung biopsy 5, 6
• The six-minute walk test can be helpful in measuring the effect of ongoing intervention 2
• Care of patients with chronic dyspnea typically requires a multidisciplinary approach 2