Does this help any?

However, in WPW, an extra electrical pathway exists between the atria
and the ventricles. This extra pathway may at times encourage a rapid
rhythm. Instead of allowing the next heart beat to begin at the SA
node, the extra pathway can "pick up" an electrical impulse in the
ventricles and send it abnormally back upward to the atria. When this
happens, the impulse begins to travel abnormally in a rapid, circular
manner, causing a rapid heart rate.

Jimbo