2-DIMENSIONAL ECHOCARDIOGRAPHIC EVALUATION OF VENTRICULAR SYSTOLIC FUNCTION IN HUMAN FETUSES WITH DUCTAL CONSTRICTION

Ventricular systolic function was assessed in fetuses, 18 with and 18 without constriction of the ductus arteriosus by serial two-dimensiona l and Doppler echocardiographic studies. Ductal constriction was defin ed as maximum systolic velocity of > 140 cm/s and diastolic flow veloc ity of > 30 cm/s. Ventricular end-diastolic and end-systolic areas wer e measured from a four-chamber view and area shortening fraction (SF) was calculated: area SF =(area in end-diastole - area in end-systole)/ area in end-diastole. In fetuses with ductal constriction, right ventr icular end-diastolic and end-systolic areas were significantly increas ed and right ventricular area SF decreased significantly compared with those values in fetuses without ductal constriction (186+/-48 vs. 150 +/-30mm(2), 112+/-34 vs. 81 +/- 19 mm(2) and 0.40 +/- 0.05 vs. 0.47 +/ - 0.03, respectively, p < 0.01) without any significant changes in lef t ventricular area SF. Serial studies were available in eight ductal c onstriction fetuses before and during indomethacin administration, and after withdrawal of the drug for a mean of 24 h. Both systolic and di astolic ductal flow velocities in all fetuses returned to normal range after discontinuation of the drug. During ductal constriction during indomethacin therapy, right ventricular end-diastolic and end-systolic cavity areas were significantly larger and area SF was significantly less than those values before and after the therapy (179 +/- 38 vs. 15 7 +/- 30 and 154 +/- 27mm(2), 108 +/- 33 vs. 82 +/- 15 and 83 +/- 15 m m(2) and 0.40 +/- 0.07 vs. 0.48 +/- 0.03 and 0.46 +/- 0.03, respective ly, p < 0.01). This study suggests that ductal constriction influences right ventricular systolic performance. has also been demonstrated th at intrauterine constriction of the ductus arteriosus can result in in creased right ventricular after load and that tricuspid regurgitation or right ventricular systolic dysfunction and hydrops can occur(3,10-1 2). A recent M-mode echocardiographic study in human fetuses suggested that ductal constriction was associated with impaired right ventricul ar function(13). The accuracy of determining ventricular size from hig h-resolution ultrasound images of the heart in fetuses appears to be i mproved when area outlines of ventricles on two-dimensional echocardio graphy are used to characterize ventricular function, because this app roach does not rely on two-point measurements but rather encompasses t he entire planar outline of the ventricles(14). In this study, we eval uated the effect of ductal constriction on ventricular size and on the systolic function of the left and right ventricles using two-dimensio nal echocardiography.