What symptom is characterized by decreased heart rate and excessive salivation in poisoning cases?

The symptom characterized by decreased heart rate and excessive salivation in poisoning cases is indeed a cholinergic crisis. This condition occurs due to the overstimulation of the parasympathetic nervous system, particularly following exposure to cholinergic substances, which can include certain pesticides and nerve agents.

In a cholinergic crisis, an excess of acetylcholine at the synaptic junction leads to a variety of symptoms. The decrease in heart rate, or bradycardia, is a result of heightened vagal tone due to excessive acetylcholine acting at the muscarinic receptors in the heart. Simultaneously, the stimulation of these receptors also causes increased glandular secretions, leading to symptoms such as excessive salivation.

The other options do not have the same combination of symptoms. Cardiac arrest typically results in a very rapid heart rate prior to actual arrest, and while it may involve changes in salivation indirectly, it does not present with excessive salivation as a prominent symptom. Atropinization refers to situations where atropine is administered to counteract the effects of cholinergic toxicity, leading to symptoms opposite of those seen in a cholinergic crisis, such as increased heart rate and dry mucous membranes. Hypoglycemia presents with