Home › Pathology guides › RV volume overload (diastolic D-shape)

RV volume overload on echo: diastolic D-shape and paradoxical septal motion

Diastolic D-shape: the septum flattens in diastole, maximal at end-diastole, and the LV becomes round again at end-systole (eccentricity index > 1 at end-diastole), so the septum moves paradoxically toward the RV in systole. The RV is markedly dilated with a thin, often vigorous free wall.

Watch it in the simulator →Practise random cases

Where to look

PSAX at papillary level frozen at end-diastole (D-shape) and end-systole (round LV); apical 4-chamber for a large RV and paradoxical septal motion; look for the cause (ASD, TR, PR).

Typical wall-motion pattern

Example: RV volume overload (e.g. ASD, severe TR or PR) — diastolic D-shape

All 17 segments thicken normally.

EF in this example: 57% (Normal (≥55%)).

1 Normal2 Hypokinetic3 Akinetic4 Dyskinetic5 Aneurysmal

Ejection fraction

Across 24 simulated cases of this pattern the true EF ranged from 52% to 62% (median 56%, Normal (≥55%)). Every case in the simulator is different, so practise until your visual estimate lands in the right 5% range.

Teaching points

Volume overload: the septum flattens in DIASTOLE, maximal at end-diastole (diastolic D-shape, eccentricity index > 1 at end-diastole). At end-systole the LV is round again, so the septum moves paradoxically toward the RV during systole. The RV is markedly dilated with a thin, often vigorous free wall.
Apical 4-chamber: very large RV, frequently apex-forming; the septum bows into the LV in diastole and moves back toward the RV in systole.
Timing is the key: compare the PSAX septum at end-diastole (just after the QRS) with end-systole (just before mitral valve opening).
Ventricular ectopics: the premature beat is weak and dyssynchronous and the beat after the pause is stronger. Judge EF and wall motion on normal sinus beats only.
Atrial fibrillation: filling and EF vary from beat to beat. Average at least five beats, or use an index beat (one that follows two similar RR intervals), and avoid beats after a very short RR interval.

Common pitfalls

A round LV at end-systole does not exclude RV disease: check end-diastole. Paradoxical septal motion with normal thickening is not an RWMA (also seen after cardiac surgery and in LBBB).

Try it now: open the RV volume overload (diastolic D-shape) example with the segment overlay, then test yourself in Practice where cases are random and graded against the exact answer.