Similar situation with my father. 38 years old, big happy fella, suffered from Wolf Parkinson's White syndrome and didnt even know it. He worked weird hours and would come home from work at 11am when everyone was at school or work. Fell over in the dinning room and died from a massive heart attack. Had it happened 4 hours later my oldest sister would've been home. 4 hours prior and I would've been home. Odd to think what "could have" been. It is what it is I suppose.
Ass, I hope that (heaven forbid) Im ever in a situation like that I can react the way you did. Cool, calm and collected. Do what needs to be done and dont worry about other shit good job.