Pulmonary Embolism USMLE Step 1 Practice Question
A 34-year-old woman with a history of migraine headaches presents to the emergency department with acute-onset dyspnea and presyncope. She reports using combined oral contraceptives for the past 2 years. On examination, she is anxious, BP 92/58 mmHg, HR 128 bpm, RR 24/min, and O2 saturation 88% on room air. Arterial blood gas shows pH 7.29, PaCO2 32 mmHg, PaO2 58 mmHg, and HCO3 15 mEq/L. Bedside echocardiography reveals right ventricular dilatation with elevated RV/LV ratio. Which of the following ECG findings is most characteristic of acute right ventricular strain in this clinical scenario?
Answer choices
- AST elevation in leads II, III, and aVF with reciprocal ST depression in I and aVL
- BPeaked T waves in all precordial leads with prolonged QTc interval
- CT-wave inversion in leads V1-V3 with sinus tachycardiaCorrect answer
- DST elevation in V1-V4 with left axis deviation and wide QRS complex
- EDiffuse ST elevation with upward concave pattern typical of early repolarization
- FNew atrial fibrillation with rapid ventricular response and right axis deviation
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