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 decreases significantly compared with those values in fetuses without ductal construction (186 ± 48 vs. 150 ± 30 mm², 112 ± 34 vs. 81 ± 19 mm² 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 less than those values before and after the therapy (179 ± 38 vs. 157 ± 30 and 154 ± 27 mm², 108 ± 33 vs. 82 ± 15 and 83 ± 15 mm² 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.