What heart rate is typically produced by cardiac tissue if it becomes the pacemaker?

What heart rate is typically produced by cardiac tissue if it becomes the pacemaker?

• A. 20 to 40 beats per minute
• B. 60 to 100 beats per minute
• C. 40 to 60 beats per minute
• D. 80 to 120 beats per minute

Answer: (A)

The pace of the heart is determined by which cardiac tissue is acting as the pacemaker. The fastest automaticity tissue sets the rhythm. In a healthy system, the SA node drives at about 60–100 beats per minute. If the SA node fails and the AV node takes over, the rate slows to roughly 40–60 bpm. If both nodes fail and ventricular tissue takes over, you get a slower escape rhythm of about 20–40 bpm. So, when pacemaker tissue is actively setting the heart rate under normal conditions, you’d expect around 60–100 bpm; 20–40 bpm represents a ventricular escape rhythm, not the typical primary pacemaker pace.

The pace of the heart is determined by which cardiac tissue is acting as the pacemaker. The fastest automaticity tissue sets the rhythm. In a healthy system, the SA node drives at about 60–100 beats per minute. If the SA node fails and the AV node takes over, the rate slows to roughly 40–60 bpm. If both nodes fail and ventricular tissue takes over, you get a slower escape rhythm of about 20–40 bpm. So, when pacemaker tissue is actively setting the heart rate under normal conditions, you’d expect around 60–100 bpm; 20–40 bpm represents a ventricular escape rhythm, not the typical primary pacemaker pace.