Define bradycardia.

• A. Abnormally fast heart rate
• B. Abnormally irregular heart rate
• C. Abnormally slow heart rate
• D. Normal heart rate

Answer: (C)

Bradycardia means an abnormally slow heart rate. In adults, a resting heart rate below about 60 beats per minute is considered bradycardia. This slower rate can be normal for some people, especially well-trained athletes, but it can also indicate problems with the heart’s electrical system or result from medications or increased vagal (parasympathetic) tone. If the slow rate is severe or accompanied by symptoms like fainting, dizziness, or fatigue, it may affect cardiac output and require evaluation.

The other options don’t fit because one describes an abnormally fast heart rate (tachycardia), another describes an irregular rhythm (arrhythmia), and the last describes a normal heart rate, not bradycardia.