Speckle Tracking in fetal echocardiography – Generation of reference values of global longitudinal strain (GLS) for quantification of atrial, ventricular und biventricular fetal heart function

Objective:

Besides the angle dependent methods like Tissue Doppler and Spectral Doppler, Speckle Tracking is an angle independent method to quantify the myocardial function. The aim of this study is to generate reference values for GLS for every heart cavity to detect subclinical myocardial changes among high risk patients better in the future.

Materials and methods:

Fetal echocardiography was performed on a Toshiba Aplio 500 ultrasound system. Based on apical or basal four chamber views of the fetal heart, for every cardiac cavity, the fetal global longitudinal strain (GLS) is measured in one cardiac cycle by 2D Speckle Tracking. In addition to measuring every single heart cavity, we managed to make the values more reproducible by measuring both free walls (= biventricular strain (BVS)).

Results:

A total of n = 102 healthy fetal hearts are included. Mean gestational age is 26.3 ± 5.5 weeks. Relating to the collected GLS values, there is a significant decrease of GLS with increased gestational age. [LV (20 WKS): -17.90 ± 2.25% → LV (37 WKS): -16.39 ± 2.28%; RV (20 WKS): -17.48 ± 1.67% → RV (37 WKS): -15.79 ± 1.69%; LA (20 WKS): -35.31 ± 5.18% → LA (37 WKS): -29.10 ± 5.25%; RA (20 WKS): -36.29 ± 2.96% → RA (37 WKS): -34.13 ± 2.99%; BVS (20 WKS): -18.50 ± 1.45% → BVS (37 WKS): -17.63 ± 1.47%].

Discussion:

Speckle Tracking for all cardiac cavities and analysis of BVS was feasible and quantification of myocardial function was possible. Following studies need to clarify the heart function among high risk patients related to these reference values.