epicardial ICDS in kids???? Can you share expereinces?

I have a 7 year old who was recently diagnosed with HCM-- because she has a severely large septum (4.0) she is being recommended for an ICD ASAP---but at this age/size it would have to be epicardial which I'm worried about---so I wonder about experiences any have had with epicardial not using veins, but directly attached to the heart and/or waiting it out until a child is bigger--hoping/praying/carrying an AED? ICDs in kids with HCM with huge septums can require extra leads etc because sometimes they won't work on the testing shock...too much muscle..

Experiences or thoughts would be GREATLY appreciated! We have to make this huge decision for her..