Maybe the decision should have come a lot earlier, but I guess hope is the last thing to leave you. On 60-70 % of my intervall session I have to stop due to arrythmia. Not only does this make it hard to do races. It makes it impossible to sustain any good training.
After dialouge with my doctors, my next step is to capture the arrythmia on EKG. Easier said than done, but a neccessary step to make a potential 3rd heart operation possible.