Following ICD implantation, you will typically be advised not to lift heavy objects or raise the arm on the side of your implant above shoulder height for four to six weeks. This is for two reasons.
First, the incision site needs time to heal without being put under physical strain. Second, and more importantly, the leads need time to become securely anchored in the heart wall — a process called lead maturation. Vigorous arm movement and heavy lifting in the early weeks can dislodge a lead before it has properly bedded in, which would require the procedure to be repeated.
Your clinical team will advise you on the specific restrictions for your situation. Most people can gradually return to normal arm movements and light activity within a few weeks, with heavier lifting and overhead activity following at six to eight weeks.