20 Mitral valve prolapse
Instruction
Examination
• Midsystolic click followed by late or midsystolic murmur
• Look for features of Marfan syndrome (high arched palate, arm span greater than height).
Notes
• Squatting will bring the midsystolic click closer to the second heart sound and decrease the duration of the murmur.
• A Valsalva manoeuvre and standing have the opposite effect.
• The midsystolic murmur begins after the first heart sound; the late systolic murmurs begin after the first heart sound but continue to or through the second heart sound (S2). Both types of murmur may have a crescendo–decrescendo configuration
Questions
What are eponyms for mitral valve prolapse?
Barlow syndrome (Br Heart J 1968;30:203), click–murmur syndrome, floppy mitral valve.
What is the prevalence in the normal population?
The new awareness that the mitral valve is saddle shaped rather than a planar valve has resulted in new echocardiographic definition for mitral valve prolapse as one or both mitral leaflets exhibit at least 2 mm displacement superior to the long-axis annular plane (a line connecting the annular hinge points), with or without leaflet thickening (Fig. 20.1). With this new description, the prevalence of prolapse is estimated at 2–3%, and is equally distributed between men and women.