Acetylcholine decreases permeability of the sinus node to potassium, effectively hypopolarizing it

Acetylcholine closes the sodium channels of the sinus node, effectively hyperpolarizing it

Acetylcholine opens the calcium channels of the cardiac myocytes, effectively delaying repolarization

Acetylcholine closes the sodium channels of the sinus node, effectively hypopolarizing it

Acetylcholine increases permeability to potassium in of the sinus node, effectively hyperpolarizing it