Résumé
Fetal echocardiogram has developed into a reliable tool for prenatal diagnosis of congenital heart disease. It is also used to evaluate ventricular function. Recently, Tissue Doppler Imaging (TDI) has been introduced to evaluate ventricular functions especially in ischaemic heart disease. The objective of this study was to evaluate myocardial velocities and heart motions of the normal fetal heart by using TDI. The TDI was preformed in 28 fetal hearts with a gestational age of 20-35 wks (Mean 29 +/- 3.7 wks) to evaluate myocardial velocities and heart motion. The Toshiba, Power Vision, machine with 3.75 and 5 MHz transducers was used with an appropriate setting of colour-coded tissue velocities. The apical four chamber and apical or parasternal long axis views were the standard planes for measuring myocardial velocities and evaluating the heart motions. The results showed the myocardial velocities of the posterior wall of the left ventricle during the early, mid, and late systolic phases were 1.5 +/- 0.2, 2.1 +/- 0.9, and 1.0+0.5 cm/sec and early, mid, and late diastolic phases were 1.3 +/- 0.7, 1.9 +/- 0.8, and 1.1 +/- 0.7 cm/sec respectively. The myocardial velocity of the anterior wall of the right ventricle during the early, mid, and late systolic phases were 1.7 +/- 0.9, 1.7 +/- 0.6, and 1.0 +/- 0.6 cm/sec and early, mid, and late diastolic phases were 1.1 +/- 0.6, 1.8 +/- 0.7, and 1.5 +/- 1.0 cm/sec respectively. The myocardial velocity of the interventricular septum could not be measured due to the abnormal septal motion and the total fetal heart movement during the cardiac cycle. The fetal heart had anterior displacement during systole and posterior translation during diastole and also had counter-clockwise rotation during the systolic phase. CONCLUSION: Using the TDI to evaluate myocardial velocities of the fetal heart is limited by the angle of ultrasound beam and the total fetal heart motion. The fetal heart movement is similar to the newborn or young adult heart.