User's Manual

67
Antitachycardia Functions
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Figure 13: In DDD mode without mode conversion (shown in upper graphic),
every second P wave triggers a ventricular pace during an atrial tachycardia.
In the DDD mode with mode conversion (shown in the lower graphic), an
atrial sensed event occurring in the atrial refractory period restarts the atrial
refractory period without the basic interval being restarted. This results in
DVI response for the duration of the atrial tachycardia.
This leads to non-P-wave-triggered AV-sequential pacing at the basic
rate for the duration of the atrial tachycardia. In DDD, DDT/A and
DDT/V modes, the pacemaker paces in the atrium and ventricle; in
VDD mode it paces only in the ventricle.
In rate-adaptive modes, the pacemaker paces at the sensor rate during
atrial tachycardia.