A 73-year-old male whom you have been treating for chest pain has suddenly become unconscious and has stopped breathing. you immediately check for a pulse. the most likely finding is:

It is most likely that no pulse can be felt when the male being treated for chest pain falls unconscious.  The chest pain experienced by the 73-year-old male is most likely because of the due heart attack. The unconsciousness experienced by the patient is the cardiac syncope, and it is possible (more so if he has a family history of it) that the patient experienced sudden death during this syncope.

Hence, the answer is 'no pulse'.