He probably means a pacemaker/defibulator. The term has become pretty interchangable anymore. Pacemakers set the rate. Defibs kick your heart in the @55 when it starts doing stupid ****, and alot of units are both in 1 case.
Dont worry man you'll do fine. I know in the short term it's scary but at far as heart surgery goes putting one of them things in is like putting in a door bell and shouldnt mess you up at all. Biggest thing it will do, besides helping you out, is give me fits when I try to run a EKG on ya if you dont tell me its there.
Your EKG will show a nice little spike telling me if it's actually pacing you at the time of the EKG and basicly making your EKG useless to me, but then again I'm only a paramedic. On the plus side I can guarentee that if ya ever call 911 to go to the hospital you'll always get a paramidc rig instead of a basic life support rig . . . and we have MORPHINE