[Diagnosis and therapy of fetal brady-arrhythmia]

Fetal rhythm disorders are one cause of intrauterine bradycardia. Diagnosis can be made by fetal echocardiography. Echocardiographic pattern and clinical course of the 4 most important fetal bradyarrhythmias are described and compared to the corresponding CTG findings. Intermittent sinus bradycardia, atrial extrasystoles with 2:1 block and ventricular bigemini have a good prognosis, whereas the outcome of the fetus with congenital atrioventricular (av)-block is depending upon degree of bradycardia and association of congenital heart malformation. The CTG feature of bigeminal blocked atrial or ventricular extrasystoles is characterized by rapid change of fetal heart rate between two different frequency levels. In sinus bradycardia or in congenital av-block no typical CTG pattern is evident. Longlasting or repetitive bradycardia should stimulate fetal echocardiography to detect rhythm disorders in order to better plan the further course of pregnancy.