Mitral chordal-leaflet-myocardial interactions in mitral valve prolapse

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Mechanics

Background:

• The submitral apparatus is crucial for maintaining myocardial geometry and annular-papillary continuity.
• In mitral valve prolapse (MVP), abnormal chordae and leaflets can disrupt this continuity, causing apparent discordant motion in the basal inferolateral wall.
• This study investigated delayed inferolateral wall motion in MVP patients.

Purpose of the Study:

• To test the hypothesis that basal inferolateral wall inward motion is delayed in MVP.
• To determine if this delay correlates with MVP severity.
• To explore time to peak transverse displacement (TPD) as a method to assess these interactions.

Main Methods:

• Thirty MVP patients and matched controls underwent stress echocardiography.
• Speckle-tracking echocardiography measured TPD of the inferolateral wall relative to the anteroseptal wall.
• TPD differences were analyzed raw, normalized to RR interval, and as a percentage of anteroseptal TPD.

Main Results:

• Inferolateral wall TPD was significantly delayed in MVP patients compared to controls, both at rest and peak stress.
• This delay was evident in both basal and basal-mid segments.
• TPD delay did not correlate significantly with prolapse severity.

Conclusions:

• Inferolateral wall TPD is delayed in MVP, indicating altered myocardial mechanics.
• TPD offers a novel approach to characterize chordal-leaflet-myocardial interactions in MVP.
• The findings suggest that perceived wall motion abnormalities in MVP during stress echo may be physiological, providing new mechanistic insights.