The significance of fetal electrocardiography in the diagnosis of intrauterine bradyarrhythmia.

From 11 cases of fetal bradycardia diagnosed by monitoring of 130 fetal electrocardiograms (ECG's) in high-risk pregnancies we have presented our experience in three selected cases of fetal bradyarrthythmia. Case 1 revealed on ECG blocked atrial premature beats simulating an extreme sinus bradycardia sequentially followed by conducted atrial premature beats. In case 2 we diagnosed ventricular premature beats in the form of persistent bigeminy which was controlled by intravenous propranolol. The last case illustrated the phenomenon of aberrant ventricular conduction known to occur in adult cardiology. The electrophysiologic basis of the variable arrhythmias was discussed. Detailed analysis of repeated direct fetal ECG's provided us with the diagnosis and understanding of the electrophysiologic mechanisms underlying the rhythm disturbances. This consequently determined the pharmacologic therapy and the obstetric approach relevant to each case. We have shown that by direct fetal electrocardiography it is possible to analyze accurately the rhythm disturbances. Persistent fetal bradycardia does not always signify fetal distress. We hope that this will lead to closer teamwork between the obstetrician and the cardiologist which will give an impetus to the future development of "fetal cardiology," thereby enhancing our understanding of the electrophysiology of the fetal heart.