RV/LV basal diameter ratio

RV/LV · Apical 4-chamber at end-diastole, basal diameters of both ventricles without foreshortening

Normal range & thresholds

<1.0 normal. >1.0 is a PH sign (ESC/ERS 2022) ^[8]; in acute PE, RV/LV ≥1.0 on echo defines RV dysfunction for risk stratification ^[124].

Pathophysiology

The RV is normally about two-thirds of the LV width. Acute pressure overload dilates the thin RV within hours; chronic overload dilates it more slowly with hypertrophy.

Raised by

• PE, PH, RV infarction, ARVC, ASD, severe TR/PR

Lowered by

—

Technique & pitfalls

• Same frame, same view; avoid an LV-focused view that under-measures the RV ^[3].

Pseudo-change & artefact

• Foreshortening; rotation; small LV from under-filling exaggerates the ratio.

Treatment thresholds

• Intermediate-risk PE classification with troponin ^[124]; PH probability ^[8].

Next step

• TAPSE/PASP, McConnell sign, 60/60 sign in suspected PE ^[147,148].

Drugs

Reperfusion in PE; decongestion.

Reversibility

Normalises after PE resolution in most survivors.