What is the initial workup for a patient presenting with chest pain in the emergency room (ER)?

Initial Workup for Chest Pain in the Emergency Room

The initial workup for a patient presenting with chest pain in the emergency room should include a 12-lead ECG within 10 minutes of arrival, measurement of cardiac troponin (preferably high-sensitivity assays), and a focused cardiovascular examination, followed by chest radiography within 30 minutes. 1

Immediate Assessment (First 10 Minutes)

• 12-lead ECG: Must be performed within 10 minutes of presentation to identify ST-segment elevation or depression, T-wave inversions, or other abnormalities suggesting acute coronary syndrome (ACS)
• Focused cardiovascular examination: To identify signs of ACS or other serious causes of chest pain
• Initial vital signs: Blood pressure, heart rate, respiratory rate, oxygen saturation, temperature
• Immediate administration of aspirin 160-325 mg (chewed) unless contraindicated 1
• Oxygen administration if saturation <90% or respiratory distress present 1
• Establish IV access in patients with concerning symptoms 1

Laboratory Tests (First 30 Minutes)

• Cardiac troponin measurement: Preferably high-sensitivity assays 1
  • Serial measurements recommended (1-3 hours for high-sensitivity troponin, 3-6 hours for conventional assays) to identify rising/falling patterns 1
• Complete blood count
• Basic metabolic panel
• Coagulation studies (if pulmonary embolism is suspected)

Imaging (First 30 Minutes)

• Chest radiography: To evaluate alternative cardiac, pulmonary, and thoracic causes of chest pain 1
• Transthoracic echocardiography: To evaluate ventricular and valvular function, detect wall motion abnormalities, and identify pericardial effusion 1

Risk Stratification

• Use validated risk scores to categorize patients into low, intermediate, and high-risk strata:
  • HEART Score: Score ≤3 has excellent negative predictive value (99.4%) for major adverse cardiac events (MACE) at 6 weeks 1, 2
  • TIMI Risk Score: For unstable angina/NSTEMI 1
  • EDACS: Another validated tool for risk stratification 1

Differential Diagnosis Considerations

Tailor workup based on clinical presentation patterns:

• Acute Coronary Syndrome: Diaphoresis, tachypnea, tachycardia; exam may be normal in uncomplicated cases 1
• Aortic Dissection: Severe pain with abrupt onset, pulse differential, widened mediastinum on CXR 1
• Pulmonary Embolism: Tachycardia + dyspnea (>90%), pain with inspiration 1
• Pneumothorax: Unilateral decreased/absent breath sounds, dyspnea 1
• Pericarditis: Fever, pleuritic pain worse in supine position, friction rub 1

Special Considerations

• Elderly patients (≥75 years): Consider ACS when accompanying symptoms like shortness of breath, syncope, or acute delirium are present 1
• Language barriers: Use formal translation services 1
• Low-risk patients: May be considered for discharge with outpatient follow-up after appropriate evaluation 1

Advanced Testing (Based on Initial Evaluation)

For patients with non-diagnostic ECG and normal initial troponin but intermediate risk:

• Serial troponin measurements
• Stress testing modalities may be considered after ruling out acute disease

Common Pitfalls to Avoid

• Relying on a single troponin measurement: Serial measurements are essential to detect rising/falling patterns 1
• Overlooking atypical presentations: Especially in elderly, diabetic patients, and women who may present without classic chest pain
• Discharging very early presenters (<3 hours from symptom onset) without adequate observation, as initial troponin may be falsely negative 2
• Failing to recognize non-coronary causes of elevated troponin (e.g., myocarditis, pulmonary embolism)