Which term describes an abnormally slow heart rate?

• A. Arrhythmia
• B. Endocarditis
• C. Bradycardia
• D. Tachycardia

Answer: (C)

A resting heart rate slower than normal is called bradycardia. In adults, normal resting rates are typically between 60 and 100 beats per minute; when the rate drops below about 60 bpm, we describe it as bradycardia. This term specifies a slow rate, unlike tachycardia, which means a fast heart rate (often over 100 bpm), and arrhythmia, which refers to any abnormal rhythm (which can be slow, fast, or irregular). Endocarditis is an infection of the heart’s inner lining or valves and is not a rate description. So the term for an abnormally slow heart rate is bradycardia.