What type of pacing is used in patients experiencing failure of the SA node?

What type of pacing is used in patients experiencing failure of the SA node?

• A. Atria pacing
• B. P wave triggered pacing
• C. AV sequential pacing
• D. Ventricular pacing

Answer: (A)

In patients experiencing failure of the SA node, atrial pacing is used to stimulate the atria directly. The SA node is responsible for initiating the electrical impulses that control the heart's rhythm. When it fails, the normal impulse generation is disrupted, leading to potential bradycardia or asystole. Atrial pacing involves using an external pacemaker to deliver electrical impulses directly to the atrial myocardium, ensuring that atrial contraction and subsequent ventricular filling occur. This helps maintain an appropriate heart rate and rhythm by bypassing the malfunctioning SA node and stimulating the heart actively.

While other types of pacing exist, such as ventricular pacing or AV sequential pacing, they cater to different conditions or areas of cardiac dysfunction. Ventricular pacing would stimulate the ventricles directly, bypassing atrial contraction, and is typically used in cases where the AV node is not conducting impulses properly. AV sequential pacing aims to synchronize atrial and ventricular contractions, primarily used for specific heart block situations. In this case, however, the reliance on the atrial function underscores the necessity of atrial pacing for managing SA node failure effectively.