Hi, i would like to know what is an extra accessory pathway to the heart? when i was child a doctor diagnosed me that.

Short circuit: Consider your heart as wired up in a specific pattern. The upper chamber is suppose to fire off (contract) first with an electrical impulse sent down to the lower chamber to contract a short time later. That is the main pathway.Some people will have a second pathway that may sometimes compete with the main. It is like an electrical short circuit. It can trigger uncoordinated contractions.