LV eccentricity index & septal shape

LVEI, D-sign · PSAX at the papillary muscles: D2 (anteroposterior) / D1 (septal–lateral) in end-systole and end-diastole

Normal range & thresholds

Normal 1.0 in both phases. >1.1 indicates septal flattening — a category-A sign in the ESC/ERS PH probability ^[8,166].

• Systolic flattening → RV pressure overload; diastolic flattening → RV volume overload ^[166].

Pathophysiology

The septum bows toward the ventricle with the lower transmural pressure. When RV pressure approaches LV pressure in systole, the septum flattens and the LV becomes D-shaped; in volume overload flattening is greatest in diastole, when RV filling dominates ^[166].

Raised by

• PH (systolic), acute PE (both), ASD and severe TR (diastolic), constriction (respiratory)

Lowered by

—

Technique & pitfalls

• True short axis at the papillary muscles; identify end-systole and end-diastole on the ECG.

Pseudo-change & artefact

• Oblique cuts; post-operative septal motion; LBBB.

Treatment thresholds

• Contributes to PH probability and PE risk assessment ^[8,124].

Next step

• TR velocity, RV size and function; RV/LV ratio (card 64).

Drugs

Relief of RV pressure/volume load restores shape.

Reversibility

Reversible with the load.