[Changes in maternal cardiovascular parameter during tocolysis and in the dorsal position shock syndrome (author's...

Maternal circulatory parameters and fetal heart rate were measured in 25 healthy pregnant women in the last trimenon during treatment with Fenoterol, Fenoterol in combination with Verapamil and Verapamil alone. Dosages were used in accordance with the tocolytic guidelines from Weidinger and Wiest. We were able to demonstrate that the betamimetic Fenoterol alone and in combination with the Ca++-antagonist Verapamil strongly increases the maternal heart rate an the maternal cardiac output whereas the peripheral resistance decreases accordingly. The average blood pressure stayed leveled, so that a decreased uterine blood flow cannot be assumed under betamimetics from the maternal cardiovascular point of view. However, there are indications for an increased placental blood flow during tocolysis. The betamimetic drug show no significant effect on the fetal heart rate. Additional application of the Ca++-antagonist Verapamil during tocolysis with Fenoterol (in dosages usually used for tocolysis) doesn't change cardiovascular reactions caused by Fenoterol. Change in position from supine to left lateral position caused a short term increase in the maternal cardiac output even noted in pregnant women without a clinically observed cavasyndrom. These changes of maternal cardiac output are comparable with those in orthostatic stress situations.