Tearing Chest Pain With Inferior ST Elevation
58-year-old man presents with sudden severe anterior chest pain that began while lifting a heavy box 45 minutes ago. He describes it as tearing and radiating to the interscapular region. He has hypertension but no prior cardiac disease. Vital signs: right arm blood pressure 178/102 mm Hg, left arm 142/84 mm Hg, heart rate 108 beats/min, respiratory rate 22/min, SpO2 96% on room air. He is diaphoretic and anxious. ECG shows 2 mm ST elevation in leads II, III, and aVF with reciprocal depression in aVL. Bedside ultrasound shows no pericardial effusion; the aortic root is not well visualized. Troponin is pending. The nearest PCI center is 30 minutes away; CT angiography is available in 90 minutes at a nearby facility. Fibrinolysis is available in the ED.
1. What is the most likely diagnosis, and why would fibrinolysis be dangerous?
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The most likely diagnosis is acute aortic dissection (Stanford type A) complicated by inferior ST-elevation myocardial infarction from right coronary artery involvement. The tearing pain radiating to the back and the interarm blood pressure differential (36 mm Hg) are highly suggestive. Inferior STEMI can be caused by dissection extending into the right coronary ostium. Fibrinolysis is dangerous because it can cause hemorrhagic pericardial tamponade, pleural hemorrhage, or extension of the dissection; it is contraindicated when dissection is suspected. The priority is to exclude dissection with CT angiography or transesophageal echocardiography before any reperfusion. If the patient becomes unstable, bedside TEE is preferred. Do not give aspirin or heparin until dissection is excluded, because they increase bleeding risk. This is a judgment call: the ECG looks like a STEMI, but the history and exam point to a surgical emergency.
2. What are the immediate management priorities, including blood pressure control and analgesia?
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Immediate priorities are blood pressure and heart rate control, analgesia, and definitive imaging. Give IV labetalol in boluses (e.g., 10-20 mg) or an esmolol infusion to target heart rate 60-80 beats/min and systolic blood pressure 100-120 mm Hg, as tolerated. If beta-blockade is insufficient, add a vasodilator such as nicardipine; never use a vasodilator before beta-blockade because reflex tachycardia can increase shear stress. Give fentanyl for pain. Obtain large-bore IV access, type and crossmatch, and keep the patient in a monitored area. Avoid thrombolytics and anticoagulation. If hypotension develops, consider tamponade, rupture, or myocardial ischemia; perform bedside ultrasound and pericardiocentesis if tamponade is present. Prepare for emergent cardiothoracic surgery.
3. How would you determine disposition and diagnostic strategy?
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Disposition depends on stability and imaging availability. If the patient is stable, obtain CT angiography of the chest, abdomen, and pelvis immediately; if CT is unavailable or the patient is too unstable, use bedside transesophageal echocardiography. The nearest PCI center is 30 minutes away, but do not transfer for PCI before excluding dissection. If dissection is confirmed, arrange emergent transfer to a cardiothoracic surgical center; do not give fibrinolytics. If dissection is excluded and STEMI is confirmed, proceed with primary PCI. If CT angiography is 90 minutes away and the patient is stable, the risk of delay must be balanced against the risk of a missed dissection; in this case, the pretest probability is high enough that imaging is mandatory. Document the reasoning and involve cardiology and cardiothoracic surgery early.