Thanks for writing us..
You are having ICD implanted, it senses your heart beat regularly whenever it is fast that is ventricular tachycardia
or ventricular fibrillation
is there it will immediately give DC shock
This arrhythmia( fastening of heart rate
) is not related to your activity, it may occur even when you are sitting, eating or sleeping.
Therefore dont be scared ,.
i think you got your querry answered if any more i will be happy to answer