Outpatient Chest Pain Workup: A Systematic Approach
For patients presenting with chest pain in the outpatient setting, an ECG should be performed immediately (within 10 minutes) unless a clear non-cardiac cause is evident, and patients with suspected ACS or other life-threatening conditions should be urgently transported to the emergency department by EMS. 1, 2
Initial Risk Assessment
Immediate Actions
- Obtain ECG within 10 minutes of arrival for all patients with chest pain 1, 2
- If ECG unavailable in office setting, immediately refer to ED 1
- Administer aspirin 162-325 mg (chewed) if ACS is suspected and not contraindicated 2
High-Risk Features Requiring Immediate ED Transfer
- Abnormal ECG (ST-elevation, ST depression, new LBBB)
- Hemodynamic instability
- Severe pain unresponsive to nitrates
- Signs of heart failure
- Syncope or near-syncope 2
Diagnostic Approach Based on Clinical Presentation
Step 1: Assess Chest Pain Characteristics
Evaluate the nature of chest pain using these descriptors:
- Higher probability of ischemia: Pressure, heaviness, tightness, squeezing, gripping, burning, retrosternal, exertional/stress-related 1
- Lower probability of ischemia: Stabbing, sharp, pleuritic, fleeting, shifting 1
Step 2: Identify Physical Examination Findings
Look for specific findings that suggest various etiologies:
| Clinical Syndrome | Key Findings |
|---|---|
| ACS | Diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3, MR murmur |
| Pulmonary Embolism | Tachycardia + dyspnea (>90% of patients), pain with inspiration |
| Aortic Dissection | Pulse differential (30% of patients), severe pain with abrupt onset |
| Pericarditis | Fever, pleuritic pain worse in supine position, friction rub |
| Pneumonia | Fever, localized pain, friction rub, dullness to percussion, egophony |
| Pneumothorax | Dyspnea and pain on inspiration, unilateral absence of breath sounds |
| Costochondritis | Tenderness of costochondral joints |
| Herpes Zoster | Pain in dermatomal distribution, characteristic rash [1] |
Management Algorithm
For Suspected ACS or Life-Threatening Conditions:
- Obtain immediate ECG (within 10 minutes)
- If concerning features present, arrange immediate EMS transport to ED 1, 2
- Do not delay transfer to obtain cardiac troponin in the office setting 1, 2
For Low-Risk Patients:
If ECG is normal and clinical suspicion for ACS is low:
For patients <40 years without cardiac history, risk factors, and with normal ECG:
Specific Testing Based on Suspected Etiology
Suspected Cardiac Etiology (Low-Intermediate Risk):
- Stress testing (exercise or pharmacologic with imaging) 4
- Consider coronary CT angiography for appropriate candidates 6
Suspected Pulmonary Embolism:
- CT pulmonary angiography for patients with high clinical suspicion 1
- D-dimer testing for low-risk patients to rule out PE 1
Suspected Myopericarditis:
- Transthoracic echocardiography to assess for wall motion abnormalities, pericardial effusion 1
- Consider cardiac MRI for definitive diagnosis 1
Suspected Aortic Pathology:
- CT angiography of chest, abdomen, and pelvis 1
Important Caveats
- Approximately 1 in 300 patients transported by private vehicle experience cardiac arrest en route, emphasizing the importance of EMS transport 2
- Cocaine and methamphetamine use should be considered as potential causes of chest pain in appropriate patients 1
- Patients experiencing chest pain during dialysis should be transferred by EMS to an acute care setting 1, 2
- Shared decision-making using validated decision aids is beneficial for low-risk patients to improve understanding and facilitate risk communication 1
By following this systematic approach, clinicians can effectively evaluate patients with chest pain in the outpatient setting while ensuring appropriate triage of high-risk patients to emergency care.