The drug of choice is isoproterenol
because the heart needs both inotropic
and chronotropic support. Devervation
tends to cause slow rhythm in the early
postoperative phase. Brain death causes
marked waxing and waning of systemic
vascular resistance as well as reduc-
tion in thyroxine, insulin, and other
hormones. The effect is to severely
stress the donor heart. This is follow-
ed by preservation and in many cases,
some degree of cardiac dysfunction
secondary to scattered subendocardial
necrosis, global injury, and edema.