Alchemy: it's not arrogance. I do believe I did rank the right kind of MD at the top of the list of who you want there. Nevertheless even with that stipulation the great equalizer is that all you have on the aircraft is O2, maybe some airway management tools (maybe not), and an AED. When there is no pulse and no respiration due to a cardiac disease process what extra is an MD going to bring to the party except the ability to pronounce and save everyone a bit of trouble? There's no access for med's, no med's, no 12 lead, no pacing, etc., etc. I suppose you could get crazy with an EpiPen somehow. But pretty much if CPR and the AED don't do the trick the party is over.