Which finding is typical for bicuspid valves on M-mode?

Which finding is typical for bicuspid valves on M-mode?

• A. Eccentric closure of valve
• B. Symmetric closure
• C. Normal motion
• D. Prolapse of cusps

Answer: (A)

Bicuspid valves create two functional leaflets instead of three, so their cusps do not close in unison. On M-mode, this asymmetry shows up as an eccentric closure line—the valve closes off-center toward the dominant cusp rather than with a symmetric, centered closure. This off-center closure is characteristic of bicuspid anatomy. Symmetric closure is what you'd expect with a normal tricuspid valve, and normal motion implies no abnormal geometry. Prolapse of cusps is a different entity, involving sagging of a leaflet, and is not the typical M-mode finding for a bicuspid valve.

Bicuspid valves create two functional leaflets instead of three, so their cusps do not close in unison. On M-mode, this asymmetry shows up as an eccentric closure line—the valve closes off-center toward the dominant cusp rather than with a symmetric, centered closure. This off-center closure is characteristic of bicuspid anatomy. Symmetric closure is what you'd expect with a normal tricuspid valve, and normal motion implies no abnormal geometry. Prolapse of cusps is a different entity, involving sagging of a leaflet, and is not the typical M-mode finding for a bicuspid valve.