User's Manual

23
Pacing Types – Modes
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Overdrive Modes
Overdrive modes reduce the probability of atrial tachycardias. In this
case, the pacing rate always lies slightly above the intrinsic atrial heart
rate. Preventive overdrive is available in modes DDD(R)+, DDT/(R)A+,
DDT/V(R)+, AAI(R)+ and AAT(R)+. For a detailed functional
description, see the "Preventive Overdrive Pacing" section.
DDD Mode
In the DDD mode, the basic interval starts with an atrial sense (A
S
) or
atrial pace event (A
p
) or a ventricular sense event not preceded by an
atrial event (VES = "ventricular extrasystole"). If no atrial sense event
occurs within the basic interval, atrial pacing takes place at the end of
the basic interval (See Figure 1), and the basic interval is restarted.