Management of Chest Pain with Normal ECG
For patients with chest pain and a normal ECG, serial cardiac troponin testing and additional diagnostic evaluation are essential next steps, as a normal ECG does not exclude acute coronary syndrome. 1
Initial Assessment and Risk Stratification
Immediate Actions
- Obtain serial ECGs, especially when clinical suspicion of ACS is high, symptoms persist, or clinical condition deteriorates 1
- Measure cardiac troponin (preferably high-sensitivity assays)
- High-sensitivity assays: Repeat at 1-2 hours
- Conventional assays: Repeat at 3-6 hours 2
- Consider supplemental ECG leads V7-V9 for patients with intermediate-to-high clinical suspicion to rule out posterior MI 1
Risk Assessment
- Apply validated risk scores (HEART, TIMI, or GRACE) to determine risk level 2
- Identify high-risk features requiring immediate intervention:
- Hemodynamic instability
- Ongoing severe chest pain unresponsive to nitrates
- Signs of heart failure
- Syncope/near-syncope 2
Diagnostic Testing
Cardiac Biomarkers
- Cardiac troponin is the most sensitive test for diagnosing acute myocardial injury 1
- Serial measurements are crucial for detecting evolving myocardial injury
- Up to 6% of patients with evolving ACS are discharged from the ED with a normal ECG 1
Imaging Studies
- Chest radiography is useful to evaluate for other potential cardiac, pulmonary, and thoracic causes of symptoms 1
- Consider additional imaging based on clinical suspicion:
- For patients with low to intermediate risk and delayed presentation (>3 hours from symptom onset), stress testing may be appropriate 3
- For patients with multiple potential causes of chest pain, CT angiography with "triple rule-out" protocol may be considered to simultaneously assess for coronary disease, pulmonary embolism, and aortic pathology 4
Treatment Considerations
Pharmacologic Therapy
- For suspected angina, nitroglycerin can be administered:
- One sublingual tablet (0.4 mg) dissolved under the tongue
- May repeat approximately every 5 minutes until chest pain is relieved
- If pain persists after 3 tablets in 15 minutes, or is different than typically experienced, seek emergency help 5
Disposition Decisions
- Patients with positive cardiac biomarkers, ischemic ECG changes (even if developed during observation), hemodynamic instability, or high-risk features should be admitted 2
- Consider observation unit admission for patients with intermediate risk and negative initial workup, or those requiring stress testing 2
- Low-risk patients with negative serial troponins, normal or unchanged ECGs, alternative diagnosis established, or resolved symptoms may be candidates for discharge with appropriate follow-up 2
Common Pitfalls to Avoid
- Relying solely on a single normal ECG to rule out ACS - serial ECGs are essential 1
- Using nitroglycerin response as a definitive diagnostic test 2
- Discharging patients with ongoing symptoms without adequate evaluation 2
- Forgetting about non-cardiac life-threatening causes of chest pain (aortic dissection, pulmonary embolism) 2
- Failing to recognize that patients with normal ECGs may have left circumflex or right coronary artery occlusions and posterior wall ischemia 1
Special Populations
- Women may present with atypical symptoms like nausea and shortness of breath 2
- Elderly patients may present with shortness of breath, syncope, delirium, or falls rather than classic chest pain 2
- Diabetic patients may have atypical presentations 2
Remember that early definitive diagnostic testing has been associated with lower rates of return visits and adverse outcomes compared to no diagnostic evaluation during the index hospitalization 6. A normal ECG alone is not sufficient to exclude significant coronary artery disease in patients presenting with chest pain.