23-04: Acute Right Ventricular Myocardial Infarction

ECG Findings

• Any ST elevation > 0.5 mm (0.05 mV) in right-sided leads (V₁R-V₆R).

• Simultaneous ST elevation in lead V₁ with ST-depression in lead V₂ strongly suggests right ventricular (RV) myocardial infarction (MI).

• Often associated with inferior MI and/or posterior MI.

Pearls

1. ECG changes of RV MI are subtle and easily missed. Obtain a right-sided ECG in any patient with inferior STEMI or in a patient with a significant hypotensive response to nitrates.

2. A right-sided ECG is obtained by placing right-sided V leads, with V₁-V₆ in mirror-image locations on the right side of the chest. The ECG leads are then marked V₁R-V₆R. Alternatively, V₁ and V₂ leads can be placed in their usual position with leads V₃-V₆ placed in mirror image (then V₃R-V₆R). V₄R is the most sensitive lead.

3. The right ventricle is very preload dependent. As such, the administration of nitroglycerin or diuretics in the presence of acute RV infarction can precipitate profound hypotension. Avoid any preload-reducing medications in these patients and give fluids liberally to maintain blood pressure as long as the lungs remain clear. Treat hypotension in a patient with acute RV MI aggressively with fluids.