This week we will hear 2 lectures from the World Congress on ablation in children from two world authorities. In the first, Professor Jeff Kim of Texas Children's Hospital speaks about unusual accessory pathway connections and offers some insights into how to ablate them. Following Dr. Kim, Professor John Papagiannis, chief of cardiology at the Onassis Center in Greece offers us some insights into why some AVNRT is challenging to ablate and how to approach these rare but difficult cases. Why is ablation not 100% effective in children for 'simple' things like accessory pathways or AVNRT? Drs. Kim and Papagiannis provide a few insights into why there is no such thing as 'just AVNRT' or 'just a pathway'.