Problem: Indicate whether the given factor would increase or decrease heart rate. Psychological stress Acetylcholine Increased heart rate Nicotine SA node damage Hyperkalemia (high Cutting of the vagus potassium nerve concentrations in the ECF) Vagal tone Blood acidosis Normal heart rate (decline in pH) Hypercapnia (high carbon dioxide Bundle branch block levels) Parasympathetic stimulation Epinephrine Proprioceptive Thyroid hormone increase indicating Decreased heart rate movement of the joints Hypercalcemia Calcium channel blockers Exercise. Need Assignment Help?