Which of the following is least characteristic of an apparent life-threatening event in an infant?

• A. Brief loss of a pulse
• B. Apnea
• C. Color change
• D. Limp muscle tone

Answer: (A)

An apparent life-threatening event is defined by episodes in infants that involve breathing cessation (apnea), color change (often pallor or cyanosis), and reduced muscle tone (limpness), sometimes with choking or gagging. The key idea is that these events are frightening and show respiratory or tone changes, but they don’t necessarily mean the heart has stopped beating.

A brief loss of pulse is least characteristic because ALTEs center on breathing pauses, color changes, and limpness, with the pulse often still present or only briefly affected. A true pulseless state points more toward cardiac arrest rather than an ALTE. The other signs—apnea, color change, and limp muscle tone—are the classic features you’d expect to see in an ALTE, signaling a need for urgent evaluation and monitoring.