What are the next steps for a patient with chest pain, hardness, and nausea after a normal electrocardiogram (ECG) test?

Management of Chest Pain with Normal ECG

A normal ECG does not exclude acute coronary syndrome (ACS)—you must obtain serial cardiac troponins immediately and perform repeat ECGs, as up to 6% of patients with evolving ACS are discharged from the emergency department with a normal initial ECG. 1

Immediate Next Steps

Serial Cardiac Troponin Measurement (Class I Recommendation)

• 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 to detect rising or falling patterns that indicate myocardial injury 1, 2
• A single troponin measurement is insufficient; serial measurements are required to identify abnormal values and dynamic patterns 3

Serial ECG Monitoring (Class I Recommendation)

• Perform repeat ECGs immediately if chest pain, hardness, or nausea recur, persist, or if the clinical condition deteriorates, as ongoing symptoms increase the likelihood of capturing evolving ischemic changes 1, 2, 3
• Continue serial ECGs every 15-30 minutes during the first hour if symptoms persist, even if the patient is currently pain-free 2
• Serial ECGs should be performed until other diagnostic testing (troponins, imaging) definitively rules out ACS 1, 3
• Compare the current ECG with previous ECGs if available, as a normal but changed ECG may reveal subtle new abnormalities 1, 3

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, 3

Additional Diagnostic Testing

Chest Radiography

• Obtain a chest radiograph to evaluate for other potential cardiac, pulmonary, and thoracic causes of symptoms including pneumonia, pneumothorax, pericarditis, pulmonary embolism, or aortic dissection 1
• This should not delay urgent evaluation for ACS 1

Observation Period

• Establish multilead ST-segment monitoring during a 6-12 hour observation period to detect dynamic changes during recurrent episodes of chest pain or silent ischemia 1
• Obtain a 12-lead ECG during any new episode of chest pain and compare with a tracing obtained when symptoms have resolved 1

Risk Stratification After Initial Testing

High-Risk Features Requiring Admission and Urgent Intervention

• Recurrent or persistent ischemic chest pain despite medical therapy 1, 2
• Dynamic ECG changes on serial tracings (ST-segment depression >1 mm, T-wave inversions >1 mm, or transient ST-segment elevation) 1, 2
• Positive second troponin measurement or rising pattern 1, 2
• Hemodynamic instability (hypotension, pulmonary rales) 1, 2
• Life-threatening arrhythmias (repetitive ventricular tachycardia, ventricular fibrillation) 1, 2
• Diabetes mellitus in the context of suspected ACS 1, 2

For high-risk patients: Admit to the hospital with continuous cardiac monitoring and consider urgent coronary angiography 1, 2, 3

Low-Risk Criteria Allowing Potential Discharge

• No recurrent chest pain after 6-12 hours of observation 2
• Normal or unchanged ECG on serial testing 2
• Two negative troponin measurements (initial and 6-12 hour) 2
• No high-risk features present 2

For low-risk patients: Consider an early stress test to provoke ischemia before discharge, with outpatient follow-up within 72 hours 2

Intermediate-Risk Patients

• Continue observation in the chest pain unit or emergency department with serial ECGs and troponins until the 6-12 hour mark 2, 3
• Consider anatomic or functional testing (such as coronary CT angiography or stress testing) before discharge 2, 3

Critical Pitfalls to Avoid

• Never rely on a single normal ECG to discharge a patient with ongoing chest pain or high clinical suspicion for ACS—this is the most dangerous error in chest pain evaluation 1, 3, 4
• Around 5% of patients with normal electrocardiograms who were discharged from the emergency department were ultimately found to have either acute myocardial infarction or unstable angina 1
• A completely normal ECG recorded during an episode of significant chest pain should direct attention to other possible causes (pericarditis, pulmonary embolism, aortic dissection, gastrointestinal causes), but only after ACS is excluded with serial troponins 1
• Left ventricular hypertrophy, bundle branch blocks, and ventricular pacing can mask signs of ischemia or injury on the initial ECG 1
• Do not delay repeat ECGs waiting for scheduled intervals if symptoms change; symptom-driven timing takes priority 2, 3