I am sorry to hear about the medical condition of your father. Illnesses are as much a trial for the caretakers as mich as they are for the ill.
Going for an open heart surgery in his age is dangerous. Hope there is another solution for his condition.
Hopefully, for at least another 3-4 years after which, his pacemaker will anyway need to change.
Walid sahib k liay buht c duain. 💖