Transient Fetal Atrioventricular Block: A Series of Four Cases and
Approach to Management
Fetal atrioventricular block (AVB) is a failure of conduction from atria
to ventricles. Immune- and non-immune-mediated forms occur, especially
in association with congenital heart disease. Second-degree (2°) AVB may
be reversible with dexamethasone and IVIG in immune-mediated disease.
However, once third-degree AVB develops, it is deemed irreversible with
need for a pacemaker and risk for cardiomyopathy. Rarely, 2° AVB is a
transient, benign phenomenon in the immature conduction system. Few case
series of transient AVB have been reported, but a management approach
has not been defined. We report four patients with self-resolving,
non-immune fetal AVB and outline a management strategy.