What pacemaker mode was described for this patient?

• A. VVI
• B. DDD
• C. AAI
• D. DDI

Answer: (B)

The key idea is coordinating pacing in both chambers to preserve atrioventricular synchrony. The described patient needs pacing in both the atrium and the ventricle, with the device able to sense in both chambers and respond to that sensing in two ways (either triggering pacing or inhibiting it as needed). This setup keeps the atrial and ventricular contractions coordinated, which improves cardiac output when sinus node dysfunction or AV block is present.

That’s why the dual-chamber pacing and sensing mode with dual response to sensing is the best fit. It paces both chambers, senses activity in both, and can either trigger pacing after a sensed event or inhibit pacing when intrinsic activity is present, maintaining proper AV timing. Other modes either pace only one chamber or don’t track atrial activity to coordinate the ventricle, which can worsen synchrony when AV conduction is impaired.