Which of the following is a physiologic criterion that would prompt action if the heart rate exceeds 140 beats per minute?

• A. HR <60/min
• B. RR 16/min
• C. SBP 110 mmHg
• D. HR >140/min

Answer: (D)

A heart rate that climbs above a high threshold signals a tachyarrhythmia that can quickly compromise cardiac output. When the rate is this rapid, there’s less time for the ventricles to fill between beats, so stroke volume drops. If the heart continues to beat this fast, perfusion to vital organs can decline, leading to hypotension, chest pain, confusion, or shock, which is why action is warranted.

The other numbers describe states that don’t reflect a dangerous fast rhythm requiring same-episode intervention: a heart rate below 60 is bradycardia, not tachycardia; a respiratory rate of 16 is normal; a systolic blood pressure of 110 mmHg is within normal range for many adults. So, the velocity of the heart rate itself is the key cue here, making that criterion the one that would prompt action.