Diagnose It Answer — April 4, 2026

67-year-old male arrives via EMS with crushing substernal chest pain radiating to his left arm and jaw, onset approximately 4 hours ago. He rates it 9/10. He is diaphoretic, pale, and anxious. His wife called 911 when he wouldn't let go of his chest.

History of hypertension, hyperlipidemia, and type 2 diabetes. Smokes one pack per day for 30 years. Father died of a 'heart attack' at age 62. He took two aspirin at home when the pain started. No prior cardiac history or procedures.

BP 158/96 mmHg, HR 102 bpm (sinus tachycardia), RR 22 breaths/min, SpO2 94% on room air, Temp 37.1°C. Patient is visibly uncomfortable, clutching his chest, and has cool, clammy skin on exam.

12-lead ECG obtained within 3 minutes of arrival shows 3mm ST elevation in leads II, III, and aVF with reciprocal ST depression in leads I and aVL, consistent with an inferior wall event. Cath lab activation initiated immediately. IV access established, supplemental O2 applied.

Troponin I initial draw: 2.8 ng/mL (elevated; normal <0.04 ng/mL). CK-MB elevated at 48 U/L. BMP: glucose 224 mg/dL, creatinine 1.1 mg/dL, potassium 3.8 mEq/L. CBC within normal limits. Chest X-ray shows mild pulmonary vascular congestion.