All of the following are the potential causes of bradycardia, EXCEPT:

Appeared in: BTSC Staff Nurse 30July-2025

Explanation

Fever is the correct answer because it is the exception; it causes tachycardia (an increased heart rate), not bradycardia.
During a fever, the body's metabolic rate increases to fight off infection or inflammation.
This increased metabolism raises the body's demand for oxygen.
To meet this demand, the sinoatrial (SA) node fires more rapidly, leading to an increase in heart rate.
Typically, the heart rate increases by about 10 beats per minute for every 1°C rise in body temperature.

Option B: Hypothyroidism is a well-known cause of bradycardia.
Option C: Beta-blocker drugs are a common pharmacological cause of bradycardia.
Option D: An 'athlete's heart' refers to the physiological cardiac remodeling in well-trained athletes, which includes a lower resting heart rate (sinus bradycardia).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Factors Affecting Heart Rate (Bradycardia vs. Tachycardia) as background academic context rather than a clinical decision trigger.
When a nurse identifies bradycardia, the first step is to assess if the patient is symptomatic (e.g., dizzy, confused, short of breath, hypotensive). Asymptomatic bradycardia in an athlete is normal, but symptomatic bradycardia is a medical concern.
It is crucial to review the patient's medication administration record (MAR) for drugs that can cause bradycardia, such as beta-blockers, calcium channel blockers, and digoxin, before administration and especially if a low heart rate is noted.
What if? If a patient on a beta-blocker for hypertension develops a high fever, their heart rate may not increase as expected (a blunted tachycardic response). The nurse should monitor for signs of inadequate cardiac output, as the heart cannot compensate for the increased metabolic demand.

How to Approach the Question

First, understand the question's format. It's an 'EXCEPT' question, meaning you need to find the option that does not fit the condition described in the stem.
Identify the core concept: 'bradycardia,' which is a slow heart rate (less than 60 bpm).
Evaluate each option one by one to determine its effect on heart rate.
Option A (fever): Recall that fever increases metabolism and heart rate. This is the opposite of bradycardia.
Option B (hypothyroidism): Recall that an underactive thyroid slows down bodily functions, including heart rate.
Option C (beta-blockers): Recall that this class of drugs is designed to slow the heart rate.

Concept Tested & Keywords

Q7BDPuUyG3IWJqNGbOLlgm

E6 Nursing Fundamentals Taylor p. 124-126

E6 Medicine Harrison 22e Part 1 p. 1961-1963

Practise the full BTSC Staff Nurse 30July-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.