My character ends up killing himself in order to be a heart donor. Problem is how does he kill himself without damaging the heart? Also, there needs to be enough time for EMT’s to reach him before his heart stops. Therefore he needs to be brain dead only . . . Is it something he could plan or is it too far fetched? For instance, a shot to the head?
Very interesting if not morbid question you ask here. It sounds like what this character is trying to accomplish is some sort of directed organ donation upon his death. His demise would have to ensure brain death, but also ensure that paramedics arrive in time to at least establish a heartbeat and get him to the hospital. There is a narrow window for this to happen. The most common time frame given for brain death is lack of oxygen for four to six minutes after the heart stops beating.
This character would have to time his heartbeat stopping and then EMS arriving around four to six minutes after. I actually would probably not choose a gunshot wound to the head. There could be a couple of things problematic with this. EMS might not choose to treat if the wound looked particularly devastating. Also, if there were damage to the facial structures, particularly the airway itself, resuscitation to even get a heartbeat back would be challenging.
I think an injury caused from anoxia (or lack of oxygen) would be your best choice. Of those, I would think drowning, hanging, ingestion of sleeping pills and/or drugs (that wouldn’t cause heart damage), and possibly carbon monoxide exposure might be your best options in my opinion. However, there is discussion in the literature whether or not it is wise to donate the organs from someone who died as a result of carbon monoxide poisoning.
Hope this helped and good luck with this story!