What is the recommended outpatient workup for a patient with chest pain and a normal electrocardiogram (EKG)?

Outpatient Workup for Chest Pain with Normal ECG

For patients with chest pain and a normal electrocardiogram, the recommended outpatient workup should include serial ECGs, cardiac troponin measurements, and risk stratification to guide further testing such as coronary CT angiography or stress testing based on clinical suspicion. 1, 2

Initial Assessment

• Serial ECGs: Even with an initial normal ECG, serial ECGs should be performed if:

  • Clinical suspicion of ACS remains high
  • Symptoms are persistent or worsen
  • Clinical condition deteriorates 1

• Cardiac Biomarkers:

  • High-sensitivity cardiac troponin (preferred) should be measured serially to identify abnormal values and rising/falling patterns indicative of myocardial injury 1, 2
  • Serial measurements are crucial as up to 6% of patients with evolving ACS may be discharged with a normal ECG 1

• Chest Radiography:

  • Useful to evaluate for other potential cardiac, pulmonary, and thoracic causes of symptoms 1, 2

Risk Stratification

Risk stratification should categorize patients into low, intermediate, and high-risk groups to guide further testing:

High-Risk Features (Consider Invasive Coronary Angiography):

• Persistent symptoms despite normal initial ECG
• Multiple cardiac risk factors
• Known coronary artery disease
• Diabetes, especially in elderly patients
• Abnormal troponin values 1

Intermediate-Risk Features (Consider Anatomic or Functional Testing):

• Atypical symptoms but concerning risk factors
• Equivocal troponin results
• Intermittent symptoms 1

Low-Risk Features (Consider Deferring Testing):

• Non-exertional pain
• Pain reproducible with palpation
• Brief duration of symptoms
• Normal vital signs
• Normal serial ECGs and troponins 2

Specific Testing Based on Risk Level

For Intermediate to High-Risk Patients:

• Supplemental ECG leads: Consider leads V7-V9 to rule out posterior MI if clinical suspicion remains high despite normal standard ECG 1, 2

• Anatomic Testing:

  • Coronary CT Angiography (CCTA): Preferred initial imaging modality for patients with suspected ACS and normal ECG 2
  • Provides comprehensive assessment of both cardiac and non-cardiac causes of chest pain 3, 4

• Functional Testing:

  • Stress Testing: Exercise ECG, stress echocardiography, or nuclear stress testing based on patient's ability to exercise and baseline ECG interpretability 2
  • Myocardial Perfusion Imaging (SPECT): Particularly useful for patients with normal or non-diagnostic ECG as it has high sensitivity and specificity 5

For Low-Risk Patients:

• Consider discharge with outpatient follow-up if serial ECGs and troponins remain normal 2
• Optional testing may include coronary artery calcium (CAC) scoring to assess atherosclerotic burden 1

Additional Considerations

• Non-cardiac Causes: Evaluate for common non-cardiac causes of chest pain including:

  • Pulmonary embolism (consider D-dimer testing if low pre-test probability)
  • Pneumonia (look for fever, localized chest pain, egophony)
  • Pneumothorax (unilateral absence of breath sounds)
  • Costochondritis (tenderness of costochondral joints)
  • Esophageal disorders 2, 6

• Clinical Pearls:

  • A normal ECG does not exclude ACS - overreliance on a normal ECG in a patient with classic anginal symptoms is dangerous 7
  • The history remains the most important diagnostic tool in chest pain evaluation 7
  • Delayed transfer to the ED for troponin testing should be avoided for patients initially evaluated in an office setting 1, 2

By following this systematic approach to chest pain evaluation in patients with normal ECG, clinicians can effectively identify those at risk for adverse cardiac events while avoiding unnecessary testing in low-risk individuals.