Ddd; Ddi - Abbott Merlin PSA EX3100 Help Manual

DDD

(Dual-Chamber Pacing, Sensing, and Inhibition; Atrial Tracking)
The DDD Mode is a dual-chamber, atrial-based timing mode in which increases or decreases in
the sensed atrial rate are duplicated by similar changes in the ventricular rate. Sensed P-waves or
R-waves inhibit output pulses, while no intrinsic activity during the alert periods result in delivered
pulses.
Figure 9. DDD Mode timing diagram

DDI

(Dual-Chamber Pacing, Sensing, and Inhibition; No Atrial Tracking)
The DDI mode is a non-tracking, dual-chamber mode in which sensed atrial activity does not
cause a change in timing. Atrial tachycardias do not result in increased pacing rates.
25