Two-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-dimensional and Doppler echocardiographic studies. Ductal constriction was defined as maximum systolic velocity of > 140 cm/s and diastolic flow velocity of > 30 cm/s. Ventricular end-diastolic and end-systolic areas were 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 ventricular end-diastolic and end-systolic areas were significantly increased 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 left ventricular area SF. Serial studies were available in eight ductal constriction fetuses before and during indomethacin administration, and after withdrawal of the drug for a mean of 24 h. Both systolic and diastolic 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. 157 +/- 30 and 154 +/- 27mm(2), 108 +/- 33 vs. 82 +/- 15 and 83 +/- 15 mm(2) and 0.40 +/- 0.07 vs. 0.48 +/- 0.03 and 0.46 +/- 0.03, respectively, p < 0.01). This study suggests that ductal constriction influences right ventricular systolic performance. has also been demonstrated that intrauterine constriction of the ductus arteriosus can result in increased right ventricular after load and that tricuspid regurgitation or right ventricular systolic dysfunction and hydrops can occur(3,10-12). A recent M-mode echocardiographic study in human fetuses suggested that ductal constriction was associated with impaired right ventricular function(13). The accuracy of determining ventricular size from high-resolution ultrasound images of the heart in fetuses appears to be improved when area outlines of ventricles on two-dimensional echocardiography are used to characterize ventricular function, because this approach does not rely on two-point measurements but rather encompasses the entire planar outline of the ventricles(14). In this study, we evaluated the effect of ductal constriction on ventricular size and on the systolic function of the left and right ventricles using two-dimensional echocardiography.