Artificial pacemaker is implanted when there is damage to

Options

A. SA node
B. AV node
C. both SA node and AV nodes
D. AV bundle

Answer

### Step-by-Step Solution:

1. **Understanding the Function of the Heart**: The heart functions through a series of electrical signals that coordinate its contractions. The sinoatrial (SA) node is the natural pacemaker of the heart, initiating these electrical impulses.

2. **Identifying the Role of the SA Node**: The SA node is responsible for setting the rhythm of the heartbeat. If the SA node is damaged, it can lead to irregular heartbeats or a significantly slowed heart rate.

3. **Recognizing the Need for an Artificial Pacemaker**: An artificial pacemaker is a medical device that is implanted to help regulate the heartbeat. It is used when the heart's natural pacemaker (the SA node) is not functioning properly.

4. **Considering Other Nodes**: While the atrioventricular (AV) node plays a role in the conduction pathway of the heart, it does not initiate the heartbeat. Damage to the AV node can lead to conduction issues but does not typically require a pacemaker unless it significantly affects heart function.

5. **Conclusion**: An artificial pacemaker is primarily implanted when there is damage to the SA node. This is because the SA node is crucial for initiating the heartbeat and maintaining a regular rhythm.

### Final Answer:
**An artificial pacemaker is implanted when there is damage to the SA node.**

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