P19.01: Application of different frame rates in two‐dimensional speckle‐tracking in fetal echocardiography and their influence on strain analysis

Abstract

Frame rates (FR) used for strain analysis assessed by speckle tracking in fetal echocardiography show a huge variation. Due to high fetal heart rates, appropriate high FR are requested for application in the fetus. The aim of this study was to investigate the influence of the FR on strain analysis in two-dimensional (2D) speckle tracking. A prospective cross-sectional study was performed. Based on an apical or basal four-chamber view of the fetal heart, cine loops were acquired on a Toshiba Aplio 500 system. Each loop was digitally stored twice: firstly as a DICOM (digital imaging and communications in medicine) file with a FR of 60 frames per second (fps), secondly with the original FR (acoustic FR = AFR). For each loop, fetal global longitudinal peak systolic strain (LPSS) values of both, left (LV) and right ventricle (RV), were assessed by 2D Wall Motion tracking. A total of n=48 healthy fetuses were included. Mean gestational age was 26.5 ± 5.5 weeks. The AFR was 129 ± 23 fps. Relating to global LPSS values of both ventricles, there was a significant difference between DICOM FR and AFR (LV: -17.3% ± 3.6% (DICOM FR) vs. -15.0% ± 3.1% (AFR); RV: -15.9% ± 3.2% (DICOM FR) vs. -14.0% ± 3.1% (AFR); p<0.001). Fetal LPSS values of both, LV and RV, assessed with high AFR, were significantly lower than the corresponding LPSS value analysed with DICOM 60 fps. Ongoing studies need to clarify the correlation of LPSS values acquired with different FR.