NREMT Paramedic

Answer: C - A drug that is a chronotropic agent is one that affects the heart rate; chrono- refers to time. Some will have positive chronotropic effects and accelerate the rate, and those with negative chronotropic effects will depress it. The vagus nerve is responsible for regulating the heart’s resting rate. The vagus nerve is also called cranial nerve X and arises from the base of the brain. The vagus nerve is a primary parasympathetic nerve that innervates the heart.