Ace the 2026 CCT Challenge – Boost Your Career with Cardiographic Confidence!

A DDD pacemaker is designed to pace both the atria and the ventricles of the heart, specifically the right atrium and the right ventricle. This mode of pacing is called "DDD" because it allows for Dual chamber pacing (the "D" for both the atrium and ventricle), with the additional capability of sensing (the final "D") in both chambers.

When a DDD pacemaker is used, it monitors the electrical activity of the heart and can initiate pacing when necessary to maintain a coordinated rhythm between the atria and ventricles. This coordination is crucial for effective heart function as it ensures that the atrial contraction occurs prior to the ventricular contraction, promoting optimal filling of the ventricles and efficient cardiac output.

In summary, a DDD pacemaker paces the right atrium and the right ventricle, allowing for synchronized activity between these chambers, reflecting the configuration described in the correct answer.