Fetal color-coded tissue Doppler echocardiography: experiences with the “tracking method” in normal fetuses

ObjectiveUltrasound-based tissue Doppler imaging has opened new perspectives for non-invasive quantification of global, as well as regional, myocardial function. We therefore studied fetal hearts using the “tracking method” in order to assess its feasibility and changes of fetal myocardial velocities throughout gestation.Study designIn 89 healthy fetuses color-coded tissue Doppler echocardiography (TDE) was prospectively conducted for further offline-analysis of global and regional myocardial function of the basal segment. Maximum tissue velocities at systole (S), in the early filling phase of diastole (E) and during atrial contraction (A) were estimated from three consecutive cardiac cycles.ResultsWithin a selected time limit of 15 min, raw data acquisition was possible in 60 of the 89 fetuses (67%). From the stored samples, velocities of S, E and A-wave could be obtained in 76% with good reproducibility for septal and right wall velocities. During gestation all velocities increased but to a greater extent at the right and left ventricular wall compared to the interventricular septum. The A-wave velocity was higher than E-wave velocity in all basal segments. Throughout gestation, the increase in E-wave was higher, resulting in an increase of the E-wave/A-wave ratio.ConclusionTissue Doppler echocardiography using the tracking method in fetal hearts is practical during routine clinical examination, but it is time consuming and requires highly experienced observers The knowledge of myocardial velocities in normal pregnancies is essential in detecting pathologies.