What is the fundamental function of a pacemaker in bradyarrhythmias?

• A. To decrease heart rate during bradycardia.
• B. To maintain heart rate by delivering electrical impulses to pace the heart.
• C. To measure blood pressure.
• D. To shock the heart during tachyarrhythmias.

Answer: (B)

In bradyarrhythmias, the heart rate is too slow, which can reduce cardiac output and cause symptoms like dizziness or fainting. The pacemaker’s fundamental role is to keep the heart beating at an adequate rate by delivering electrical impulses that pace the heart when the intrinsic rhythm falls below the set threshold. It can pace the atria, ventricles, or both, and may operate in demand mode (only pacing when the heart is slow) or in a fixed rate mode, depending on the patient’s needs. This sustained pacing restores a more normal heart rate and improves perfusion, addressing the core problem of bradycardia. It does not lower heart rate, measure blood pressure, or deliver shocks for tachyarrhythmias—those functions belong to other devices or therapies.