Describe how the nerve impulse travels in the heart?

The brain can influence the heart in two ways. Sympathetic and parasympathetic stimulation.

Parasympathetic stimulation of the heart is through the vagus nerve.

Sympathetic stimulation of the heart is via cervical and thoracic splanchnic nerves.

The heart has its own pacemaker cells, so the brain only changes the rate and contractility of the heart.