Which of the following drugs will decrease hea rate in a patient with a normal hea rate but will have little effect on hea rate in a cardiac transplant recipient

Ref-KDT 6/e p127 Nor-adrenaline decreases the hea rate due to reflex stimulaton of baroreteptors. These reflexes are lost in a transplanted hea. however, by its acton, it can produe tachycardia phenylephiine is a selective alpha1 agonist. It has no direct eftect on the hea but produes bradyardi due to reflex stimulation o baro-receptors. These retlexes are lost in a translanted hea. Therelore, it produces no etfect on hea.