Which of the following is a sign of an eating disorder related to heart rate?

• A. Hypertension
• B. Tachycardia at rest
• C. Normal heart rate
• D. Bradycardia with HR < 50 bpm during day and HR < 45 bpm at night

Answer: (D)

Bradycardia at rest is a classic sign tied to eating disorders. When someone is malnourished, the body conserves energy by slowing the heart and lowering the metabolic rate. This shift toward increased parasympathetic (vagal) influence on the heart reduces the heart rate, and the reduction tends to be more noticeable during rest, especially at night when the natural circadian dip is exaggerated in the context of starvation. That’s why resting heart rates can be under 50 beats per minute during the day and under 45 at night. Hypertension is not typical in eating disorders, and a normal heart rate wouldn’t point to the condition. A markedly slow resting heart rate thus signals the need for medical evaluation and careful management of nutrition and electrolytes during treatment.