[Fetal ECG and arrhythmias]. / Fetales EKG und Arrhythmien.

ABSTRACT

The normal fetal heart rate ranges between 110 und 180 beats per minute (bpm). Intrauterine arrhythmias are not an uncommon finding. Fetal echocardiography (ECG) allows for correct diagnosis of the arrhythmia, which is prerequisite for decision making and treatment. Most fetal rhythm disturbances are the result of premature atrial contractions and are of little clinical significance. Intrauterine bradycardias (heart rate < 110 bpm) result from sinus node dysfunction, complete AV block and nonconducted atrial bigeminy. Isolated complete heart block related to maternal anti-SSA/Ro or SSB/La auto-antibodies is irreversible in almost all fetuses. Anti-inflammatory therapy and chronotropic medication may improve outcome. Newborn babies often require pacemaker implantation to augment cardiac output. Intrauterine tachycardias (heart rate > 180 bpm) are most commonly related to supraventricular tachycardia and atrial flutter. Specific antiarrhythmic medication is available to stop the arrhythmia and to prevent hemodynamic deterioration.