How should I initially evaluate and manage a 76-year-old patient presenting with chest pain and a normal 12-lead electrocardiogram?

Initial Evaluation and Management of a 76-Year-Old with Chest Pain and Normal ECG

A normal ECG does not exclude acute coronary syndrome—immediately measure high-sensitivity cardiac troponin and perform serial ECGs, as up to 6% of patients with evolving ACS are inappropriately discharged with a normal initial ECG. 1, 2, 3

Immediate Diagnostic Actions

Cardiac Biomarkers

• Measure high-sensitivity cardiac troponin immediately if not already obtained, as troponin is the most sensitive test for myocardial injury and necessary to implement appropriate therapy 1, 3
• Repeat troponin at 6-12 hours from symptom onset to detect rising or falling patterns that indicate myocardial injury 4, 1, 2
• A single negative troponin drawn early may miss evolving myocardial injury and should never be used alone for disposition decisions 1

Serial ECG Monitoring

• Perform repeat ECGs immediately if chest pain persists, recurs, or if the clinical condition changes (new dyspnea, diaphoresis, hemodynamic instability, arrhythmias) 1, 2, 3
• Continue serial ECGs every 15-30 minutes during the first hour if symptoms persist, even if currently pain-free 2, 3
• Do not wait for scheduled intervals—symptom-driven timing takes priority 1
• Serial 12-lead ECG monitoring increases detection of AMI by 34% compared to initial ECG alone 4

Additional ECG Considerations

• Obtain supplemental posterior leads (V7-V9) if clinical suspicion remains intermediate-to-high, as left circumflex or right coronary artery occlusions causing posterior wall ischemia are often "electrically silent" on standard 12-lead ECG 1
• Look for subtle findings that machine analysis often misses: isolated T-wave inversion in aVL (precedes inferior MI), biphasic T waves in V2-V3 (Wellens syndrome indicating critical LAD stenosis), or diffuse ST depression with elevation in aVR (left main or triple-vessel disease) 5, 6

Ancillary Testing

• Obtain chest radiograph to evaluate for other cardiac, pulmonary, and thoracic causes of chest pain 1

Risk Stratification

High-Risk Features Requiring Admission 1, 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

Intermediate-Risk Features 2, 3

• Age >70 years (this patient qualifies)
• Previous ischemic heart disease
• Extracardiac vascular disease (peripheral artery disease, stroke, creatinine >1.4 mg/dl)
• Multiple coronary risk factors

Low-Risk Criteria 2, 3

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

Disposition and Management

For High-Risk Patients

• Admit to monitored unit with continuous cardiac monitoring 1, 2, 3
• Initiate aspirin 162-325 mg (chewed, non-enteric-coated) immediately if no contraindications 4
• Administer anticoagulation with low molecular weight heparin or unfractionated heparin 1
• Use beta-blockers and nitrates for persistent or recurrent chest pain 1
• Consider urgent coronary angiography if recurrent ischemia, elevated troponin, or hemodynamic instability develops 1, 2

For Intermediate-Risk Patients (Including This 76-Year-Old)

• Continue observation in chest pain unit or ED with serial ECGs and troponins until the 6-12 hour mark 2, 3
• Consider anatomic or functional testing (coronary CT angiography or stress testing) before discharge 3
• Given age >70 years, this patient should not be discharged without completing serial testing and risk stratification 4

For Low-Risk Patients

• Consider early stress test to provoke ischemia before discharge 2
• Ensure outpatient cardiology follow-up within 72 hours with clear instructions to return immediately for recurrent chest pain 1

Critical Pitfalls to Avoid

• Never assume a normal ECG excludes cardiac pathology—one-third of patients with acute chest pain have a normal admission ECG, yet 5-40% have evolving myocardial infarction 1
• Never discharge without serial troponin measurements—a single negative troponin is insufficient 1, 2
• Never delay repeat ECGs waiting for scheduled intervals if symptoms change 1, 3
• Always compare current ECG with previous ECGs if available 3
• Clinical history alone has limited discrimination for short-term cardiac events (C statistic = 0.74-0.75), making objective testing essential 7