[Supraventricular tachycardia of the fetus in the 3d trimester of pregnancy following persistent supraventricular extrasystole].

Persistent supraventricular extrasystoles are antepartally, intrapartally and postpartally the most frequent form of arrhythmias, and do not cause fetal congestive heart failure (hydrops fetalis). The premature beats often disappear spontaneously prenatally, but in most cases within the first two weeks of life. The extremely rare observation of the occurrence of a supraventricular tachycardia in the 37th week of gestation in a fetus with persistent supraventricular extrasystoles from the 20th week of gestation onward and with a postnatally diagnosed Wolff-Parkinson-White syndrome is described. Because of the importance of this complication of supraventricular extrasystoles (a supraventricular tachycardia of the fetus can cause a cardiac failure with hydrops fetalis and eventually intrauterine death), it is important that all fetuses with supraventricular extrasystoles be closely monitored by frequent observation of the fetal heart rate using ultrasound (M-mode-echocardiography), cardiotocography and auscultation. Postpartally a cardiologic examination of these newborn infants is necessary, particularly in order to exclude the presence of a preexcitation.