In a 29-year-old woman with ST-segment elevation in leads V4‑V6 and T-wave inversion in leads V1‑V2, what is the most likely diagnosis and what is the appropriate acute management?

ECG Findings in a 29-Year-Old Woman: Likely Diagnosis and Management

This ECG pattern—ST elevation in V4-V6 with T-wave inversion in V1-V2—most likely represents an acute lateral STEMI requiring immediate reperfusion therapy, though the differential must include myopericarditis, Takotsubo cardiomyopathy, and early repolarization variants given the patient's young age and sex. 1

Primary Diagnostic Consideration: Lateral STEMI

The ST elevation in leads V4, V5, and V6 meets STEMI criteria if ≥1 mm (0.1 mV) in these contiguous lateral chest leads. 1 However, critical context is essential:

• Age and sex matter for ST elevation thresholds: In women under 40, the upper normal limit for J-point elevation in V2-V3 is approximately 0.15 mV, but this doesn't apply to V4-V6 where any elevation ≥0.1 mV is abnormal. 2

• The T-wave inversions in V1-V2 are NOT diagnostic on their own: In young women and adolescents, anterior T-wave inversion in V1-V3 can be a normal "juvenile pattern" or a benign finding. 2 However, when combined with ST elevation elsewhere, this pattern requires urgent evaluation.

Immediate Management Algorithm

Step 1: Assess Clinical Context (Do This Simultaneously with ECG Interpretation)

Determine if the patient has active chest pain or ischemic symptoms:

• Ongoing chest pain, dyspnea, diaphoresis, or radiation to arm/jaw suggests acute coronary occlusion requiring emergent catheterization. 2
• Recent viral illness, pleuritic chest pain, or positional pain suggests myopericarditis. 3
• Recent emotional/physical stress with apical ballooning pattern on echo suggests Takotsubo cardiomyopathy. 2

Step 2: Activate STEMI Protocol if Symptomatic

If the patient has ongoing ischemic symptoms with this ECG pattern, activate the catheterization laboratory immediately:

• Primary PCI should be performed within 90 minutes of first medical contact. 1
• Administer aspirin 162-325 mg chewed immediately unless contraindicated. 1
• Add P2Y12 inhibitor (clopidogrel 600 mg loading dose or ticagrelor 180 mg). 1
• Anticoagulation with unfractionated heparin or bivalirudin. 1

Step 3: Consider STEMI-Mimics That Require Different Management

Myopericarditis is a critical differential in young women:

• Look for PR depression in limb leads and widespread ST elevation (not just V4-V6). 3
• Pericardial friction rub on exam strongly suggests pericarditis. 3
• If suspected, obtain high-sensitivity troponin, inflammatory markers (ESR, CRP), and echocardiogram for pericardial effusion. 3
• Cardiac MRI with late gadolinium enhancement can confirm myopericarditis and exclude infarction. 3
• Critical caveat: Even if myopericarditis is suspected, if symptoms suggest ongoing ischemia, proceed to angiography—myopericarditis can coexist with coronary disease. 3

Takotsubo cardiomyopathy presents similarly but has distinct features:

• Often triggered by emotional or physical stress in postmenopausal women (though can occur in younger patients). 2
• ECG changes are usually modest and don't correlate with severity of ventricular dysfunction. 2
• Emergency angiography will show no significant culprit stenosis or thrombus. 2
• Echocardiogram shows transient apical-to-mid ventricular ballooning with basal hyperkinesis. 2
• Troponin elevation is disproportionately low relative to degree of wall motion abnormality. 2

Step 4: Obtain Additional ECG Leads if Diagnosis Unclear

If the patient is asymptomatic or symptoms have resolved:

• Obtain posterior leads (V7-V9) to evaluate for posterior MI, which can present with ST depression in V1-V3 (though this patient has T-wave inversion, not ST depression). 2
• Repeat ECG in 15-30 minutes or with symptom recurrence to look for dynamic changes. 2
• Compare to prior ECGs if available—chronic changes suggest non-ischemic etiology. 4

Key Clinical Pitfalls to Avoid

Do not dismiss this as "normal variant" without excluding acute pathology:

• While T-wave inversion in V1-V2 can be normal in young women, ST elevation in V4-V6 is NOT a normal variant. 2
• The combination of findings requires urgent evaluation even if the patient appears well. 2

Do not delay angiography if clinical suspicion for ongoing ischemia is high:

• Some patients with genuine coronary occlusion (particularly circumflex territory) may have atypical ECG presentations. 2
• Ongoing symptoms despite medical therapy mandate emergency angiography even without classic STEMI criteria. 2

Do not assume Type 2 MI without identifying a clear precipitant:

• Type 2 MI requires both troponin elevation AND an identifiable supply-demand mismatch (tachyarrhythmia, severe anemia, sepsis, hypotension). 5
• In a 29-year-old woman without obvious precipitant, assume Type 1 MI (acute coronary occlusion) until proven otherwise. 5

Risk Stratification Based on ECG Pattern

This lateral ST elevation pattern suggests:

• Likely left circumflex or obtuse marginal branch occlusion (V4-V6 distribution). 2
• Lower risk than anterior STEMI but still requires urgent reperfusion. 1
• If accompanied by inferior ST elevation (II, III, aVF), consider right ventricular involvement and obtain right-sided leads. 1

The absence of widespread ST depression with aVR elevation is reassuring:

• ST elevation in aVR with multilead ST depression suggests left main or severe multivessel disease and portends worse prognosis. 6
• This patient's pattern does not fit that high-risk profile. 6

Summary of Recommended Approach

For symptomatic patients with ongoing chest pain:

1. Activate STEMI protocol immediately
2. Administer aspirin and P2Y12 inhibitor
3. Proceed to emergency cardiac catheterization within 90 minutes
4. If angiography shows no culprit lesion, obtain cardiac MRI to evaluate for myopericarditis or Takotsubo 2, 3

For asymptomatic patients or those with resolved symptoms:

1. Obtain serial high-sensitivity troponins (0 and 1-2 hours)
2. Continuous telemetry monitoring
3. Echocardiogram to assess wall motion abnormalities
4. If troponin elevated or wall motion abnormalities present, proceed to urgent (not emergent) angiography within 24-72 hours 5
5. If troponin normal and echo normal, consider cardiac MRI or stress testing to exclude ischemia 2