Acute symptomatic sinus bradycardia usually responds to-: (A) Adrenalinea, (B) Dopamine, (C) Atropine, (D) Norepinephrines
Answer is C. Sinus bradycardia: A regular but unusually slow hea beat (50 beats/minute or less at rest). Fainting can occur with sinus bradycardia if the hea slows down even more. This can occur, for example, when the vagus nerve sends a signal to the hea that suddenly drops the hea rate Ref Harrison 20th edition pg 1456