Try not to listen to the horror stories about the implantable ICD as freqeutnly it is only the people with those stories that talk about their ICD. People who have one and never have any problems don't usually join forums or talk about their device as they are to busy living and enjoying their life.
My husband's uncle has the pacemaker and the ICD which were place at least 10 years ago and never has he had any problems with the device.
If you should need the ICD try to think of it as protection for yourself. If you believe the manufacturer, ICDs are 98% effective should your cardiac rhythm ever have the need for the ICD to kick in.
I will say a prayer that your cardiologist can correct your problem with the ablation. My thoughts are with you.