Neostigmine-induced bradycardia following recent vs remote cardiac transplantation in the same patient

This report describes the effects of neostigmine on heart rate in the same patient following recent and remote cardiac transplantation.

Eighty-six months following the first transplant, neostigmine 5.0 micrograms.kg-1 i.v. produced a 10% reduction in heart rate which was reversed by atropine 1.2 mg. For 24 months prior to this initial study, the patient experienced angina, suggesting cardiac afferent reinnervation. Three months after the second heart transplant, a second study showed that a six-fold increase in the dose of neostigmine, 30.0 micrograms.kg-1, only produced a 3.5% reduction in heart rate which was reversed by atropine 1.2 mg.

These observations indicate that neostigmine produces bradycardia following cardiac transplantation, and suggest that a greater response may be observed in remotely than in recently transplanted patients.