Hi, Welcome to HCM, After going through history of your father, he has coronary artery disease and already on pacemaker implanted. I can understand he is having pump failure( Heart Failure) that is why he is short of breath. I presume he must be on optimal medical therapy. There are few option left may be to prevent sudden death a Implantable defibrillator(AICD). If there is indication then possibly resynchronization therapy. In Ejection fraction 10% only option left is Heart transplantation. He should be on waiting list. Nobody should try to predict how long he will survive,it is ultimate truth. Please take very good care of him Good Luck. Dr.Akhilesh Dubey M.D.