Speckle Tracking in Fetal Echocardiography—Generation of Reference Values of Global Longitudinal Strain for Quantification of Atrial, Ventricular, and Biventricular Fetal Heart Function

Objectives: 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 global longitudinal strain (GLS) for every heart cavity to detect subclinical myocardial changes among high-risk patients better in the future.

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 GLS is measured in one cardiac cycle by 2D speckle racking. In addition to measure 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 weeks]: −17.90 ± 2.25% → LV [37 weeks]: −16.39 ± 2.28%; RV [20 weeks]: −17.48 ± 1.67% → RV [37 weeks]: −15.79 ± 1.69%; LA [20 weeks]: −35.31 ± 5.18% → LA [37 weeks]: −29.10 ± 5.25%; RA [20 weeks]: −36.29 ± 2.96% → RA [37 weeks]: −34.13 ± 2.99%; BVS [20 weeks]: −18.50 ± 1.45% → BVS [37 weeks]: −17.63 ± 1.47%).

Conclusion: 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.