TISSUE DOPPLER ECHOCARDIOGRAPHY (TDI) IN THE NORMAL FETUS – ANALYSIS OF THE MYOCARDIAL

Purpose: A subjective interpretation of myocardial regional motion and thickness is frequently performed during fetal echocardiography. Tissue Doppler echocardiography (TDI) has been introduced as a new method to quantify regional myocardial function in adult cardiology. There are only few studies on the fetal heart.

Methods and Materials: In fetuses without evidence of abnormalities in the second trimester pregnancy screening between 19 th and 24 th week of gestation apical four chamber view colour TDI Cineloops of 3 cardiac cycles were recorded with a high frame rate using Toshiba Aplio 80. Data were collected and later analysed offline. Placement of windows (ROI's) was in the subvalvulare plane, the middle and the apex of the myocardium of the left and right ventricle and the interventriculare septum. Thus allowing the simultaneous measurement of myocardial velocities in different regions in the same heart cycle. These results, 80 data sets, were further analysed with standard software.

Results: We are able to demonstrate inter- and intraventriculare differences in the parameter describing the performance of the heart, e.g. peak velocities, time to peak, IRT, IVC, E/A ratio. These differences can be interpreted in a physiological way.

Conclusions: Because of the observed interventriculare differences standard curves need to be established for both ventricle of the fetal heart. Before using these parameters for clinical evaluation care must be taken to define exact points and rules for measurement.