[Arrhythmias and conduction block in the newborns of mothers who had received long-term tocolytic therapy].

Serial electrocardiograms (ECGs) were studied prospectively in 48 newborns exposed in utero to prolonged tokolytic therapy to beta-sympathomimetics and in 30 newborns non-exposed in utero to beta-mimetics. Duration of exposure to tocolysis was at least 7 days, mean 51 +/- 36 days. The ECGs were made in 1-st and 3-rd day of life. The ECGs were estimated for duration the QT interval (as corrected QT-QTc) Cardiac event in 16 newborns from treated group and in 16 newborns from control group were examined in 1-st day of life on a Holter monitor. It was found that, the prolongation of QTc time, the ventricular extrasystole and the atrioventricular blocks second degree (Wenckenbach's period) were occurred more often in the newborns whose mother had taken beta-mimetic drugs then in the control group.