Q: Patients with previous heart transplant have (select one)
A) Supersensitive response to adenosine
B) No response to adenosine
Contrary to popular belief, adenosine effect is exaggerated in patients who are heart transplant recipients. It reduces calcium influx into cardiac cells by antagonizing adenylate cyclase. It also increases potassium conductance.
Denervated donor heart has increased sensitivity to circulating catecholamine and adenosine.
Koller-Strametz J, Kratochwill C, Grabenwöger M, et al. PR interval adaptation in the denervated transplanted heart. Pacing Clin Electrophysiol 1997; 20:1247.