What are the next steps if an electrocardiogram (ECG) is normal in a patient with sudden-onset chest pain that worsens with respiration?

Next Steps for Normal ECG in Patient with Sudden-Onset Chest Pain Worsening with Respiration

For a patient with sudden-onset chest pain that worsens with respiration and a normal ECG, the next step should be evaluation for pulmonary embolism, pneumothorax, pneumonia, pericarditis, or other non-coronary causes of chest pain.

Initial Assessment After Normal ECG

• A normal ECG does not exclude acute coronary syndrome (ACS) or other serious conditions; up to 6% of patients with evolving ACS are discharged from the emergency department with a normal ECG 1
• For patients with ongoing chest pain, serial ECGs should be performed to detect potential ischemic changes, especially when clinical suspicion of ACS is high 1
• Pleuritic chest pain (worsening with respiration) is more commonly associated with non-coronary causes such as pulmonary embolism, pneumothorax, pneumonia, or pericarditis 1, 2

Recommended Diagnostic Pathway

1. Cardiac Biomarker Testing

• Obtain cardiac troponin levels (preferably high-sensitivity) to rule out myocardial injury 1
• Serial troponin measurements may be necessary (0,3, and 6 hours) to detect evolving myocardial injury 1

2. Chest Radiography

• A chest radiograph is essential to evaluate for pulmonary causes of pleuritic chest pain 1
• Can help identify pneumonia, pneumothorax, pleural effusions, widened mediastinum (aortic dissection), or pulmonary congestion 1

3. Additional Testing Based on Clinical Suspicion

For suspected pulmonary embolism:

• D-dimer testing (if low-to-intermediate pretest probability) 2
• CT pulmonary angiography if D-dimer is positive or if high pretest probability 1, 3

For suspected pericarditis:

• Echocardiography to assess for pericardial effusion 1, 4
• Consider supplemental ECG leads if initial ECG is normal but clinical suspicion remains high 1

For suspected pneumothorax or pneumonia:

• Focused physical examination looking for unilateral absence of breath sounds (pneumothorax) or regional dullness to percussion (pneumonia) 1

Key Clinical Features to Guide Diagnosis

• Pulmonary embolism: Sudden onset dyspnea, pleuritic chest pain, tachycardia, hypoxemia 2, 3
• Pericarditis: Fever, pleuritic chest pain that increases in supine position, possible friction rub 1, 4
• Pneumothorax: Dyspnea and pain on inspiration, unilateral absence of breath sounds 1
• Pneumonia: Fever, localized chest pain that may be pleuritic, friction rub may be present, regional dullness to percussion 1
• Costochondritis: Tenderness of costochondral joints 1

Common Pitfalls to Avoid

• Do not rely solely on a normal ECG to exclude serious pathology, especially when symptoms are concerning 5
• Do not delay appropriate imaging studies when pleuritic chest pain is present, as conditions like pulmonary embolism require prompt diagnosis and treatment 1, 2
• Remember that some patients with ACS may present with atypical symptoms, including pleuritic chest pain, though this is less common 1
• Avoid premature diagnostic closure based on the normal ECG; maintain a broad differential diagnosis 1, 5

Special Considerations

• In patients with intermediate-to-high clinical suspicion for ACS despite a normal standard ECG, consider supplemental ECG leads V7 to V9 to rule out posterior myocardial infarction 1
• If symptoms persist or worsen despite normal initial testing, consider echocardiography to assess for wall motion abnormalities or other cardiac pathology 1
• For patients with persistent unexplained symptoms and negative initial workup, admission for observation and further evaluation may be warranted 1