Dawod Sharif1, James C. Huhta2,1, Kenneth J. Moise1, Robert Morrow1, Grace Y. Yoon1
1St. Luke's Episcopal Hospital, Houston, United States
2Division of Cardiology, Children's Hospital of Philadelphia, 34th and Civic Center Boulevard, Philadelphia, Pennsylvania 19104
Tóm tắt
AbstractThe aim of this study was to examine the fetal hemodynamic effects of terbutaline treatment and premature labor. Image‐directed pulsed and continuous wave Doppler ultrasound studies, using 3.3‐MHz and 5‐MHz transducers (GE PASII and ATL echocardiographic machines), were used to assess fetal cardiac blood velocities in three groups of pregnancies matched for menstrual age (MA). Group 1: 13 normal pregnancies, mean MA 31 weeks. Group 2: 7 women in premature labor prior to tocolytic therapy, mean MA 32 weeks. Group 3: 8 women treated with terbutaline, average dose 18.8 mg daily, for previous premature labor, mean MA 31 weeks. Heart rate averaged 150 bpm, 135 bpm, and 127 bpm in the terbutaline, premature labor, and normal groups, respectively, and each were significantly different from each other. Products of time velocity interval and heart rate at the aortic valves were 1603 cm ± 140 cm, 1413 cm ± 190 cm and 1238 cm ± 200 cm, and at the mitral valves 1102 cm ± 170 cm, 812 cm ± 110 cm, and 878 cm ± 150 cm in the terbutaline, premature labor, and the normal groups, respectively. Aortic and mitral blood velocity products of time velocity integrals and heart rates were significantly higher (p = 0.01) in the terbutaline group relative to the normal group. In addition, the terbutaline group was significantly higher than the labor group at the mitral valve (p = 0.01). There was no statistically significant difference in time velocity integrals (a measure of stroke volume) at either valve between the three groups.It is concluded that both terbutaline and premature labor are associated with higher fetal heart rates relative to normals. Higher fetal heart rates were associated with increased left‐sided cardiac blood flows. Stroke volume was constant with increased heart rate, suggesting increased cardiac contractility with both preterm labor and terbutaline treatment.
