Reference Values for Inward Displacement in the Normal Left Ventricle: A Novel Method of Regional Left Ventricular...

Area of Science:

• Cardiology
• Medical Imaging
• Physiology

Background:

• Current imaging techniques have limitations in assessing regional left ventricular (LV) function.
• Inward displacement (InD) is a novel technique measuring LV endocardial border motion for regional function assessment.
• Normal reference ranges for InD are currently unavailable for clinical application.

Purpose of the Study:

• To validate normal reference limits for Inward displacement (InD) in healthy adults across all 17 LV segments.
• To establish a clinical standard for InD measurements in normal left ventricular function.

Main Methods:

• Inward displacement (InD) was analyzed in 120 healthy subjects with normal LV ejection fraction using cardiac MRI.
• Measurements were taken from standard long-axis views, quantifying inward endocardial wall motion towards the LV center.
• InD was measured in mm and as a percentage of maximal segment contraction, averaged per segment and by LV region (base, mid-cavity, apex).

Main Results:

• The average InD across all segments was 33.4 ± 4.3%.
• InD was significantly higher in basal (32.8 ± 4.1%) and mid-cavity (38.1 ± 5.8%) segments compared to apical segments (28.6 ± 7.7%).
• Strong interobserver variability correlations (R = 0.80) were observed for InD measurements.

Conclusions:

• Clinically meaningful reference ranges for InD in individuals with normal LV function have been established.
• Inward displacement (InD) is poised to become a valuable tool for screening and assessing therapies for heart failure with reduced ejection fraction (HFrEF).