Mitral valve training › Guides › Barlow disease (bileaflet prolapse)

Barlow’s disease on echo: bileaflet prolapse and annular disjunction

What to look for: Thick, redundant leaflets of both sides billowing; a large annulus.

Key findings

• Barlow’s disease: thick (≥5 mm), redundant leaflets with prolapse of several scallops of both leaflets, elongated chords and a dilated annulus; it is often seen in younger patients.
• Mitral annular disjunction (MAD): the posterior leaflet hinge sits on the LA wall, separated from the top of the LV posterior wall; measure it in the parasternal long axis at end-systole. MAD with mitral valve prolapse is linked to ventricular arrhythmias.
• True MAD persists through the cardiac cycle; a separation seen only in systole, as the leaflet billows, is pseudo-MAD.
• There are often several jets, central or eccentric.

Grading the regurgitation (primary MR)

• Severe: vena contracta ≥7 mm, EROA ≥0.40 cm², regurgitant volume ≥60 ml, regurgitant fraction ≥50%. Mild: vena contracta <3 mm, EROA <0.20 cm², regurgitant volume <30 ml.
• Specific signs of severe MR: a flail leaflet or ruptured papillary muscle, a large flow convergence, and systolic flow reversal in the pulmonary veins; a dense, triangular CW signal and an E-wave-dominant inflow support it.
• Integrate several signs: no single measurement grades MR on its own.

Pitfalls

• Several jets: grade them together, preferably by the total regurgitant volume; a single vena contracta or PISA understates them.
• Late systolic MR is common: a peak vena contracta or PISA overstates it.

In the simulator every case varies the anatomy, the jets and the measurements: watch the lesion in Learn, then grade new cases in Practice and compare your answer with the exact one.

Related

Single-scallop prolapse · Flail leaflet (ruptured chord)

Educational simulation to use under the supervision of a clinical tutor — not for clinical use.