What is an escape beat?

What is an escape beat?

• A. A transiently failed impulse
• B. An automaticity focus emits one beat
• C. Regular pacing by the SA node
• D. A fast atrial contraction

Answer: (B)

An escape beat occurs when an ectopic pacemaker or automaticity focus within the heart takes over for a moment, usually when there's a failure of the primary pacemaker, the sinus node, to generate an impulse. This phenomenon allows the heart to maintain a rhythm when the SA node is not functioning adequately. Specifically, an escape beat is characterized by the ectopic pacemaker initiating a single beat, which serves as a "rescue" mechanism to prevent a complete cessation of cardiac activity.

The concept of an escape beat is important in understanding how to interpret EKGs, as it indicates the response of the heart to situations such as bradycardia or sinus arrest. Recognizing an escape beat can help clinicians discern underlying conditions that may be leading to irregular rhythms or periods of asystole.

In contrast, the other options provide various definitions that do not accurately capture the nature of an escape beat, such as regular pacing by the SA node, which describes normal heart rhythm rather than an escape mechanism, or transient impulse failure, which lacks the context of an ectopic focus providing a single beat.