A regular heart rate less than 60 beats per minute is described as which of the following?

• A. Sinus Bradycardia
• B. Sinus Tachycardia
• C. Normal Sinus Rhythm
• D. Atrial Fibrillation

Answer: (A)

Understanding how heart rate and rhythm are categorized helps identify sinus bradycardia. A slow but regular rhythm that originates from the sinoatrial node points to sinus bradycardia. When the heart rate is under 60 beats per minute and the rhythm remains steady with normal P waves before each QRS complex and a normal PR interval, it’s considered bradycardia of sinus origin. This differentiates it from sinus tachycardia, which is the same orderly rhythm but at a faster rate (usually over 100 bpm). Normal sinus rhythm means a rate between 60 and 100 bpm, with the same orderly, regular rhythm. Atrial fibrillation looks different: it’s irregular and often fast, with no distinct P waves and variable intervals between beats. So the best match for a regular heart rate under 60 is sinus bradycardia because it combines a slow rate with a normal, organized sinus rhythm. In clinical sedation contexts, bradycardia can be benign in some individuals (e.g., well-trained athletes) but may require assessment if symptoms or hemodynamic changes are present.