DIASTOLIC FUNCTION OF THE FETAL HEART DURING 2ND AND 3RD TRIMESTER - A PROSPECTIVE LONGITUDINAL DOPPLER-ECHOCARDIOGRAPHIC STUDY

To generate normal charts of fetal cardiac inflow velocities and to as sess physiologic changes of ventricular diastolic function, velocity w aveforms of tricuspid and mitral valves were studied longitudinally in 49 fetuses in 4 week intervals from 14 weeks gestation to term. Doppl er tracings were analyzed for: peak early (E) and peak late (A) inflow velocities, time velocity integral (TVI) of total inflow and A-wave v elocity waveforms and heart rate corrected isovolemic relaxation time. E- and A-velocity as well as total- and A-wave-TVI of both valves inc reased significantly with gestational age (P<0.001). Heart rate and A/ E ratio decreased significantly with gestational age (P < 0.001). The ratio of A-wave TVI to total TVI of both valves and heart rate correct ed isovolemic relaxation time (TVI) was constant suggesting unchanged diastolic function. This study provides normal charts for fetal cardia c inflow velocities. After 14 weeks of gestation all inflow velocities and their respective TVI's increased linearly in the growing fetal he art. There was evidence that diastolic function did not change. Area r atios and IVR should be used to determine changes in ventricular diast olic function, rather than velocity ratios.