Which ST-segment elevation pattern suggests a right ventricular MI?

Which ST-segment elevation pattern suggests a right ventricular MI?

• A. ST elevation in leads I and aVL
• B. ST elevation in leads II and III
• C. ST depression in V5-V6
• D. T-wave inversion in aVR

Answer: (D)

Right ventricular infarction is suspected when the ECG shows ST-segment elevation in the right-sided precordial leads (for example, leads positioned on the right chest, like V4R and other right-sided placements). The right ventricle lies to the right and anteriorly, so its injury is best captured by these right-sided leads, and it often accompanies an inferior wall MI due to RCA occlusion.

Patterns seen in standard limb leads or left-sided chest leads are less specific for RV involvement. ST elevation in lateral leads (I, aVL) indicates a lateral-wall MI, while ST elevation in inferior leads (II, III) points to an inferior MI. ST depression in V5–V6 can reflect reciprocal or posterior involvement, and T-wave inversion in aVR is a non-specific sign that can be seen with diffuse ischemia or multivessel disease rather than RV-specific injury.

Therefore, the hallmark of right ventricular MI on ECG is elevation in right-sided chest leads, with V4R being a classic confirmatory finding if available. Without right-sided leads, RV involvement is harder to confirm on ECG alone.