BA actually have a very advanced in-flight medical kit, including a 'body-suit' that can be worn and data (such as ECG, BP) transferred to emergency room physicians in phoenix. In addition to the excellent CC training they carry a number of additional drugs which can be administered by suitably qualified personnel.

I certainly hope that the passenger is making a recovery, it is so reassuring to know that in this type of situation the captain will do whatever (s)he deems necessary, probably at fairly significant financial cost to the airline.