Conduction system defects in three perinatal patients with arrhythmia.

The cardiac conduction systems of three patients who died in the perinatal period were studied histologically. Rhythm disturbances were observed in these patients immediately before death. The sinus node was notably hypoplastic without increase in fibrous content in all cases. The atrioventricular node was smaller than expected in all, and the entire atrioventricular conduction axis was small in two cases. This study supports the need for a detailed examination of the cardiac conduction system so as to provide a better understanding of the clinicoanatomical relation in the context of fatal perinatal arrhythmias.