A 68-year-old woman presents with severe epigastric discomfort and jaw pain for 3 hours. ECG shows ST depression of 3 mm in leads V1 through V3 with tall R waves and upright T waves in the same leads. Which of the following is the most appropriate next step to confirm the diagnosis?
- A Obtain right-sided leads V3R and V4R
- B Obtain posterior leads V7 through V9 ✓
- C Obtain a 15-lead ECG with augmented limb leads
- D Obtain serial cardiac troponins at 0 and 6 hours
Correct answer: B. Obtain posterior leads V7 through V9
Explanation
ST depression with tall R waves in V1-V3 is the mirror image of posterior MI. Posterior leads V7-V9 will show ST elevation and confirm the diagnosis, guiding urgent reperfusion. Right-sided leads are indicated in inferior STEMI to detect RV involvement. Troponin elevation alone does not distinguish STEMI equivalents requiring urgent PCI.
Reference: Braunwald's Heart Disease, 12th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.