American Board of Internal Medicine (ABIM) Certification Practice Exam

What does relative bradycardia in typhoid fever indicate?

1. A slower heart rate despite fever

2. An elevated heart rate due to dehydration

3. Normal heart rate

4. Frequent palpitations

The correct answer is: A slower heart rate despite fever

Relative bradycardia in typhoid fever is characterized by a slower heart rate despite the presence of fever. In most febrile illnesses, one would typically expect to see tachycardia, or an elevated heart rate, as the body's way of responding to infection and fever. However, in the case of typhoid fever, patients may present with an unusual finding: a heart rate that is lower than expected relative to their level of fever. This phenomenon is thought to result from the infection's effects on the autonomic nervous system and its impact on heart rate regulation. It is essential to understand that the presence of bradycardia in a febrile patient can indicate a specific type of systemic dysregulation that is often associated with typhoid fever. Thus, noting this clinical sign can be a crucial diagnostic clue in identifying typhoid fever among other febrile illnesses. Other options, such as an elevated heart rate due to dehydration, would not align with the presentation of relative bradycardia. Additionally, a normal heart rate would not characterize the term "relative bradycardia," and frequent palpitations would indicate an increased heart rate rather than a decreased one.