What is the next step in managing a patient with non-tender right-sided chest pain and a normal electrocardiogram (ECG)?

Management of Right-Sided Chest Pain with Normal ECG

Immediately measure serial cardiac troponins and perform repeat ECGs, as a single normal ECG is insufficient to exclude acute coronary syndrome (ACS), with up to 6% of patients with evolving ACS being discharged from the emergency department with a normal initial ECG. 1

Immediate Next Steps

Serial Cardiac Troponin Measurement (Class I)

• Obtain high-sensitivity cardiac troponin (cTn) immediately if not already done, as troponin is the most sensitive test for diagnosing acute myocardial injury and is necessary to implement appropriate therapy 1
• Repeat troponin measurement at 6-12 hours from symptom onset (not from presentation time) to detect rising or falling patterns that indicate myocardial injury 1, 2, 3
• A single troponin measurement drawn less than 6 hours from symptom onset is unreliable and should never be used alone to exclude ACS 2

Serial ECG Monitoring (Class I)

• Perform repeat ECGs immediately if symptoms recur, persist, or if the clinical condition deteriorates, as ongoing symptoms increase the likelihood of capturing evolving ischemic changes 1, 4
• Continue serial ECGs every 15-30 minutes during the first hour if symptoms persist, even if the patient is currently pain-free 2
• Compare current ECG with any previous ECGs available, as a normal but changed ECG may reveal subtle new abnormalities 1, 4

Consider Supplemental ECG Leads

• Obtain posterior leads (V7-V9) if clinical suspicion for ACS remains intermediate-to-high (Class IIa recommendation), as left circumflex or right coronary artery occlusions causing posterior wall ischemia are often "electrically silent" on standard 12-lead ECG 1, 4, 3
• Right-sided ECG leads should be considered when right ventricular involvement is suspected 1

Additional Diagnostic Testing

Chest Radiograph (Class I)

• Obtain a chest X-ray to evaluate for alternative cardiac, pulmonary, and thoracic causes including pneumothorax, pneumonia, rib fractures, widened mediastinum (aortic dissection), pleural effusion, or pulmonary artery enlargement (pulmonary embolism) 1, 3, 5
• The yield depends on pretest probability but should not delay urgent cardiac evaluation if ACS is suspected 1

Risk Stratification During Observation

• High-risk features requiring immediate intervention include: 2, 3

  • Recurrent or persistent ischemic chest pain despite medical therapy
  • Dynamic ECG changes on serial tracings
  • Positive second troponin measurement or rising pattern
  • Hemodynamic instability
  • Life-threatening arrhythmias
  • New or worsening heart failure

• Low-risk criteria allowing potential discharge with outpatient follow-up include: 1, 2

  • No recurrent chest pain after 6-12 hours of observation
  • Normal or unchanged ECG on serial testing
  • Two negative troponin measurements (initial and at 6-12 hours)
  • No high-risk features present

Critical Pitfalls to Avoid

Never Rely on Single Normal ECG

• Decision-making should never be based solely on a single normal or nondiagnostic ECG, as left ventricular hypertrophy, bundle branch blocks, and ventricular pacing may mask signs of ischemia or injury 1, 4
• Research demonstrates that 1-4% of patients with absolutely normal ECGs had acute myocardial infarction, and 4% of patients with nonspecific ECG abnormalities experienced MI 6

Symptom-Driven Timing Takes Priority

• Do not delay repeat ECGs waiting for scheduled intervals if symptoms change or recur; symptom-driven timing takes priority over protocol-based intervals 4, 2

Consider Alternative Life-Threatening Diagnoses

• When cardiac causes are being evaluated, simultaneously consider aortic dissection, pulmonary embolism, pericarditis, pneumothorax, and esophageal perforation as these require different urgent management 2, 5, 7
• The non-tender nature of the pain does not exclude these diagnoses 5

Disposition Algorithm

If high-risk features present: Admit to hospital with continuous cardiac monitoring and consider urgent coronary angiography 2, 3

If intermediate-risk: Continue observation in chest pain unit or ED with serial ECGs and troponins until 6-12 hour mark; consider anatomic or functional testing (coronary CT angiography or stress testing) before discharge 1, 2, 3

If low-risk with negative serial testing: Consider early stress test to provoke ischemia before discharge, with outpatient follow-up within 72 hours 1