Why there is bradycardia in dengue?

Answer 1

It is known that dengue fever can affect the heart in several ways, including weakened force and speed of contraction and slowed pulse rate. Along with some other febrile illnesses ( illnesses with fever) dengue may demonstrate "relative bradyardia", that is, heart rate lower than would be expected for a given level of fever. The mechanism is not clear but may be mediated through the immune system or may be related to an inflammation of the heart. The presence of a relatively slow heart rate in the presence of a high fever is not diagnostic for dengue but indicates the need for testing for dengue, or if testing is not available is probably sufficient indication to treat for dengue. Finally, in the terminal stages of many conditions, including severe hemorrhagic dengue fever, massive loss of fluids out of the circulatory system into the tissues may result from damage to the capillaries (the smallest blood vessels). In these circumstances the body may not be able to compensate for the low circulating volume and blood flow to the vital organs, including the brain and the heart itself may be diminished to critical levels resulting in slowing of the heart, usually as a precursor to death. This cause of bradycardia is more properly regarded as part of the complex process known as "shock" rather than as a symptom of any specific disease.