One of the common complications that we see in these patients is sinus node dysfunction, or abnormal function of the natural
pacemaker of the heart. This is due to the large amount of
surgery and scar tissue near the sinus node, which can certainly occur with an intracardiac version of the Fontan. Therefore, it is not uncommon to see heart rates this low in patients after a Fontan.
At this point, the most important fact is that she is asymptomatic.