Fetal bradycardia and sinus node dysfunction.

The study reported here is a rare case of fetal sinus bradycardia that evolved into symptomatic bradycardia after birth, at which time the implantation of a cardiac pacemaker was indicated. Fetal echocardiography was used to diagnose the type of cardiac rhythm that caused the intra-uterine bradycardia, which enabled the initiation of the appropriate therapy approach and avoided an unnecessary interruption of the pregnancy. However, the details of the sinus bradycardia were impossible to determine in utero in this case due to sinus node dysfunction. After birth, the electrocardiogram results drew attention to a potentially unusual cause of sinus bradycardia, and enabled the diagnosis of this rare disease in this infant.