Longitudinal Displacement for Left Ventricular Function Assessment

TL;DR

This study explores how much heart muscle segments move during the heartbeat, finding that this movement is reduced in people with heart dysfunction and behaves differently than traditional strain measurements.

Contribution

The study introduces longitudinal displacement as a novel measure for assessing left ventricular function and reveals its reversed basal-to-apical gradient.

Findings

Longitudinal displacement is highest in basal segments and lowest in the apex of the left ventricle.

Global longitudinal displacement is significantly reduced in patients with left ventricular dysfunction compared to healthy individuals.

Global longitudinal displacement and strain show a strong negative correlation.

Abstract

Background: Quantitative evaluation of myocardial function traditionally relies on parameters such as ejection fraction and strain. Strain, reflecting the relative change in the length of a myocardial segment over the cardiac cycle, has been extensively studied in various cardiac pathologies over the past two decades. However, the absolute length change, or longitudinal displacement, of myocardial segments during the cardiac cycle has received limited attention. This study aims to evaluate longitudinal displacement in two separate groups: healthy athletes and patients with left ventricular dysfunction, providing new insights into myocardial function assessment. Methods: Echocardiographic examinations were performed on 30 healthy football players and 30 patients with left ventricular dysfunction using speckle-tracking imaging analysis. Global and regional peak longitudinal displacement values were calculated and compared with corresponding global and regional peak longitudinal strain measurements. A manual alternative for calculating global longitudinal strain was also proposed. Results: An inverse correlation was found between regional longitudinal displacement and regional longitudinal strain. Longitudinal displacement was maximal in the basal segments and lowest in the apex of the left ventricle, exhibiting a reversed basal-to-apical gradient (17.6 ± 3.5 mm vs. 11.5 ± 2.9 mm vs. 4.22 ± 1.7 mm in basal, mid, and apical segments, respectively; p < 0.000001). Maximal longitudinal displacement was observed in the inferior and posterior walls of the left ventricle. In the 30 patients with left ventricular dysfunction, global longitudinal displacement was significantly lower than in healthy individuals (4.4 ± 1.7 mm vs. 11.7 ± 1.5 mm, p < 0.000001). Global longitudinal displacement and global longitudinal strain showed a strong negative correlation (r = −0.72, p < 0.000001). Manually calculated global longitudinal strain demonstrated good agreement with speckle-tracking-based global longitudinal strain. Conclusions: Peak longitudinal displacement can be used to evaluate both regional and global myocardial function, similarly to peak longitudinal strain. Unlike strain, longitudinal displacement exhibits a reversed basal-to-apical gradient, with the highest values at the base of the left ventricle and the lowest at the apex. Global and regional longitudinal displacement is significantly reduced in patients with left ventricular dysfunction. Global longitudinal strain can be manually calculated using displacement measurements. Further studies are needed to evaluate peak longitudinal displacement in various cardiac pathologies.

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