Its brain....Since heart is only a pumping organ. Harm to it causes heart failure and cardiovascular stun prompting demise. Be that as it may, the time taken for this is similarly more when contrasted with other case. As the blood is constantly present all over the place, Thrombosis hypoxia and pooling takes a brief period. Though harm to cerebrum on the off chance that it prompts break to conduits providing to mind causes inner drain which is extremely hazardous and hypoxia prompts demise. Since heart is the organ which minimum adapt up to hypoxia. 

Be that as it may, amusingly one can be make due with a shot in cerebrum at fringe interior draining isn't seen hugely. The individual makes due with numerous neurological issue. Unconsciousness can happens. Then again if shot in heart isn't dealt with rapidly beyond any doubt passing happens.