What is the best course of action for a 21-year-old male with chest pain and electrocardiogram (EKG) changes showing mild ST elevation in the inferior and left precordial leads, with a heart rate of 94 beats per minute (bpm) and normal sinus rhythm (NSR)?

Immediate Management of ST Elevation in a Young Adult

This 21-year-old male with chest pain and ST elevations in inferior and left precordial leads requires immediate activation of the STEMI protocol with urgent coronary angiography, even in a young patient without traditional risk factors. 1

Immediate Actions Required

Activate STEMI protocol immediately - do not delay for additional testing when ST elevation is present on ECG. 2, 1 The presence of ST elevation signifies complete or near-complete occlusion of a major coronary artery requiring immediate reperfusion therapy. 2

Time-Critical Steps:

• Transfer to catheterization laboratory immediately - target door-to-balloon time of <120 minutes from ambulance arrival to first balloon inflation. 1
• Administer dual antiplatelet therapy now: aspirin 300 mg and either ticagrelor 180 mg or clopidogrel 600 mg loading dose. 2
• Initiate anticoagulation with heparin during transfer. 2
• Do NOT wait for serial troponins or additional imaging - delaying definitive reperfusion therapy worsens outcomes and increases mortality. 1, 3

Critical Differential Diagnoses in Young Patients

While STEMI protocol activation is mandatory, consider these alternative diagnoses that can present identically in young adults:

High-Priority Alternatives:

Coronary vasospasm (Prinzmetal's angina) 2, 4:

• Can cause ST elevation identical to STEMI in young patients without atherosclerotic disease. 2
• Typically occurs at rest, often in early morning hours. 2
• Exquisitely responsive to nitroglycerin - if ST elevations resolve completely with NTG, this supports vasospasm. 2, 4
• Coronary angiography may show normal arteries or spasm can be visualized during the procedure. 2

Myopericarditis 5:

• Young patients with very high troponin levels (>15,000 ng/L) and chest pain should raise suspicion for inflammatory process. 5
• Look for PR segment depression on ECG - a subtle finding pointing to pericardial inflammation. 5
• Typically presents with diffuse ST elevations (not territorial distribution) and absence of reciprocal ST depression. 2

Spontaneous coronary artery dissection (SCAD) 5:

• Must be ruled out in young patients, particularly those without traditional risk factors. 5
• Can only be definitively diagnosed or excluded by coronary angiography. 5

Key Diagnostic Considerations During Workup

ECG Analysis:

• Compare with prior ECGs immediately if available - unchanged findings suggest benign early repolarization rather than acute process. 2, 3
• Obtain right-sided leads (V3R-V4R) - right ventricular infarction can cause marked ST elevation in both precordial and inferior leads. 6
• Obtain posterior leads (V7-V9) - approximately 4% of acute MIs show ST elevation isolated to posterior leads that is "hidden" from standard 12-lead ECG. 3
• Assess for early repolarization pattern - generally benign in asymptomatic young patients, but can mimic STEMI. 3

Bedside Echocardiography:

• Perform immediately while preparing for catheterization - do not delay transfer. 5
• Assess for regional wall motion abnormalities (RWMA) - presence supports acute coronary syndrome. 5
• Normal wall motion does NOT exclude STEMI but raises suspicion for alternative diagnoses. 5

Management Algorithm

1. Activate STEMI protocol immediately - assume STEMI until proven otherwise. 1
2. Administer antiplatelet therapy and anticoagulation during preparation for catheterization. 2
3. Give nitroglycerin - if ST elevations resolve completely, consider vasospasm but still proceed to angiography. 2, 4
4. Obtain bedside echo while preparing for transfer - assess for RWMA and LV function. 5
5. Proceed to urgent coronary angiography - this is both diagnostic and therapeutic. 1

Critical Pitfalls to Avoid

• Do not dismiss as benign early repolarization without serial ECGs and biomarkers - inappropriate reassurance can be fatal. 3
• Do not delay catheterization based on young age or absence of risk factors - spontaneous coronary dissection and premature atherosclerosis occur in young adults. 5
• Do not rely on single normal troponin - 5% of acute coronary syndromes present with normal initial biomarkers. 3
• Do not assume normal echo excludes STEMI - myopericarditis can present identically but requires different treatment. 5
• Do not confuse benign early repolarization with STEMI - inappropriate thrombolytic therapy carries unnecessary hazards, but when in doubt, proceed to angiography rather than observation. 3

Post-Angiography Considerations

If coronary angiography reveals normal arteries, cardiac MRI is the gold standard to differentiate myopericarditis from other causes and provide detailed structural information. 5 Continue antiplatelet therapy until definitive diagnosis is established. 2

If vasospasm is confirmed, initiate calcium channel blocker (verapamil 240-480 mg daily, diltiazem 180-360 mg daily, or nifedipine 60-120 mg daily) plus long-acting nitrates. 2, 4 Smoking cessation is mandatory. 2