291 Echocardiographic assessment of myocardial function using automatic functional imaging in IUGR fetuses with high risk of cardiac failure: a preliminary study

Abstract

Severe fetal vascular growth retardation leads most often spontaneously to cardiac failure and fetal death. Fetal cardiac monitoring is therefore a priority in order to decide on ideal timing for fetal extraction. The assessment of cardiac function in fetuses using conventional 2D imaging has always been challenging, due to the lack of adapted algorithm to the specific fetal cardiac geometry. Automatic Functional Imaging (AFI) is a new angle and Doppler independent technique, based on 2D analysis of the myocardial deformation (or Strain). It allows to measure the strain of a chosen myocardial region of interest (ROI): right or left ventricle or both. Assess cardiac function with AFI in fetuses with severe In Utero Growth Restriction (IUGR) and high risk of cardiac failure, and compare to normal fetuses. We recruited prospectively in a single institution 24 normal fetuses (group I), 17 fetuses with severe IUGR (estimated weight <3d percentile) and umbilical Doppler's Pulsatility Index >95th percentile (group II) and 8 fetuses with severe IUGR (estimated weight <3d percentile) without umbilical Doppler's anomaly (group III). Myocardial strain and strain rate of left, right and total ventricles (respectively LV, RV, TV) were measured from a 4 chamber view (figure 1 and 2) and compared between groups. No correlation was found between gestational age and strain and strain rate in normal fetuses. Feasibility was around 82%, and reproducibility was good. LV and TV strain was lower in group II and III compared to group I (respectively 21.9, 20.9 vs 25.1% and 19.9, 18.7 vs 22.9% (p<0,05)). Surprisingly, RV strain was not different between group I and II but was lower in group III (p<0.05). Strain rate was not different between groups. AFI is a new technique allowing cardiac function measurement in fetuses. It is of particular interest in the follow up of pregnancy with high risk of fetal cardiac failure.