What Is The Treatment For The Bleeding In The Brain And Tachycardia?

My father had a stroke in March, has attrial fib (had a defibrillator implanted in January)congestive heart failure, had 2 mild heart attacks in the past, most recently 1 1/2 years ago, had a quadruple bypass after the second heart attack. He is cognitive after the stoke but has apraxia and asphagia. He is on a feeding tube to suplement his nutrition as he has just recently been able to swallow some pureed foods. He has many health issues. He is currently being monitored for a tiny bleed in his brain and tachycardia. What I'm fearful of is him having a heart attack and the defibrillator kicking in and keeping him going. The family, knowing his wishes, have submitted a dnr on him, but my question is, would the defibrillator keep bringing him back (and causing him to suffer more) if he were to have another heart attack?