Why does bradycardia present in dengue?

Relative bradycardia: A definition of bradycardia is a heart rate (hr) < 60 beats per minute. Usually, hr increases by approx 10bpm per degree of fever.High fever with normal hr is "relative bradycardia;" hr is lower than expected. Relative bradycardia occurs in dengue for reasons felt to be related to the immune system, but exact mechanism as yet is unknown, to my knowledge.

Uncertain.: Whether it&#x27;s a direct action of the virus, an immune response, cytokine action or the result of another circulating substance is uncertain. However, the association is well-documented.