Transition from fetal to neonatal life: Changes in cardiac function assessed by speckle-tracking echocardiography

OBJECTIVE: Assessment of cardiac function by speckle-tracking (2D-S) echocardiography in the transitional period from fetal to neonatal life in a healthy population. METHODS: Ultrasound assessment of cardiac function of 30 healthy fetuses at the gestational age of 28 weeks, and follow-up after birth using 2-D strain derived novel parameters such as longitudinal strain (S), strain rate (SR), tissue velocities, MPI- and E/E'-index, E/A- and E'/A'-rate of both right (RV) and left ventricles (LV) and interventricular septum (IVS) and comparison to conventionally measured cardiac stroke volume (SV), cardiac output (CO) and ejection fraction (EF). RESULTS: Ultrasound 2D-S performance and analysis were technically feasible and reproducible in all 30 fetuses and in the neonatal period. In fetuses, tissue velocities and SR measurements were homogenous for all regions of interest in both ventricles, and strain increased from apex to base and was significantly higher in the RV compared to LV. All calculated indices were almost identical for RV and LV. After birth, strain and strain rate exhibited significantly lower values, and systolic tissue velocities were higher in comparison to fetal values in both chambers and in all regions of interest. CONCLUSION: Speckle-tracking echocardiography is a feasible and reproducible technique in analyzing both fetal and newborn cardiac functions. Therefore, it might be useful in clinical routine examinations and give new insights in transitional physiology.