What is the immediate next step in managing a 38‑year‑old woman with a 10‑day history of exertional dyspnea, left‑sided chest pain radiating to the back, intermittent four‑limb numbness, bilateral pitting leg edema, treadmill test (TMT) showing ST‑segment depression in leads II, III, aVF and reciprocal ST‑segment elevation in leads I, aVL, V2‑V6 consistent with an acute anterior ST‑segment elevation myocardial infarction (STEMI), normal echocardiogram (Echo), and cervical spine magnetic resonance imaging (MRI) revealing mild C4‑5 and C5‑6 disc bulges?

Immediate Emergency Coronary Angiography is Indicated

This patient requires immediate cardiac catheterization and primary percutaneous coronary intervention (PCI) without delay—the treadmill test demonstrates a STEMI-equivalent pattern with extensive ST-segment elevation in anterior and lateral leads (I, aVL, V2-V6), and she has ongoing symptoms with bilateral leg edema suggesting hemodynamic compromise. 1, 2

Critical Recognition: This is Acute STEMI Despite Normal Echo

The TMT findings show ST-segment elevation in leads I, aVL, and V2-V6, which represents acute anterolateral myocardial infarction requiring immediate reperfusion therapy. 1 The concomitant ST-depression in inferior leads (II, III, aVF) represents reciprocal changes that actually strengthen—not contradict—the diagnosis of anterior STEMI. 3

The normal echocardiogram does not exclude acute coronary occlusion. 1 Wall motion abnormalities may not yet be apparent in very early presentation, and echo has limited sensitivity for detecting acute ischemia before established necrosis. 1 The European Society of Cardiology explicitly states that ongoing suspicion of myocardial ischemia despite medical therapy is an indication for emergency coronary angiography even without diagnostic imaging findings. 1

Why Immediate Catheterization Takes Priority

Do NOT wait for cardiac biomarkers

The European Society of Cardiology guidelines explicitly prohibit waiting for troponin results when ECG shows ST-segment elevation with ischemic symptoms. 2, 3 The ECG diagnosis alone is sufficient to activate the cardiac catheterization laboratory. 1

Time-critical reperfusion window

• Primary PCI should be performed within 120 minutes of first medical contact when STEMI is confirmed. 1, 4, 2
• Every minute of delay results in ongoing myocardial necrosis with progressive loss of salvageable myocardium. 3
• If PCI cannot be achieved within 120 minutes, fibrinolytic therapy should be administered immediately, with greatest benefit occurring within the first 6 hours. 4

High-risk features demanding urgent intervention

This patient has multiple markers of severe disease:

• Bilateral pitting leg edema suggests elevated filling pressures and possible cardiogenic pulmonary congestion. 1
• Exertional dyspnea indicates hemodynamic compromise. 1
• Extensive ST-elevation territory (anterolateral distribution) implies large area of myocardium at risk. 1
• 38-year-old woman with atypical presentation (numbness, back pain) represents a demographic at risk for delayed diagnosis. 1, 4

Immediate Pre-Catheterization Management

While activating the catheterization laboratory, initiate:

• Aspirin 160-325 mg chewed immediately plus a P2Y12 inhibitor (ticagrelor 180 mg or prasugrel 60 mg if no contraindications). 4, 3
• Morphine titrated intravenously for pain relief and to reduce sympathetic activation. 1, 4
• Oxygen only if saturation <90%—routine oxygen is not indicated and may be harmful. 1
• Continuous ECG monitoring with defibrillation capability for potentially fatal arrhythmias. 3
• Unfractionated heparin or low-molecular-weight heparin during transfer. 1, 2

Why the Cervical Spine Findings are Red Herrings

The C4-5 and C5-6 disc bulges with mild narrowing do not explain:

• ST-segment elevation on ECG (cervical radiculopathy does not cause ECG changes). 1
• Bilateral pitting leg edema (this is cardiac, not neurologic). 1
• Exertional chest pain radiating to back (the temporal relationship to exertion indicates cardiac ischemia). 1

The intermittent four-limb numbness may represent anxiety/hyperventilation in the setting of acute cardiac ischemia, or could be evaluated later after the life-threatening cardiac condition is addressed. 1

Common Pitfalls to Avoid

Do not order stress testing—the patient has already demonstrated ST-segment elevation during exertion on the TMT, which IS the positive stress test. Further stress testing is contraindicated and dangerous in acute MI. 2

Do not assume the normal echo excludes acute coronary syndrome—wall motion abnormalities lag behind ECG changes, and the absence of wall motion abnormalities does not exclude major myocardial infarction in the acute setting. 1

Do not delay for serial troponins—elevated markers should not delay reperfusion, and waiting for "definitive" biochemical confirmation in the presence of diagnostic ECG changes worsens outcomes. 2, 3

Do not attribute symptoms to cervical spine disease—the combination of exertional chest pain, dyspnea, leg edema, and ST-segment elevation on ECG represents acute coronary occlusion until proven otherwise. 1

The Definitive Next Step

Activate the cardiac catheterization laboratory immediately and transfer the patient for emergency coronary angiography with intent to perform primary PCI. 1, 2 If coronary occlusion is confirmed (which is highly likely given the ECG pattern), proceed directly to revascularization. 1, 4 The goal is door-to-balloon time <90 minutes. 3