User's Manual

Pacing Types – Modes

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VDI Mode

The VDI mode is derived from the VVI mode. In contrast to the latter,

the VDI mode allows intra-atrial events to be recorded. The timing

corresponds to the VVI mode, however. The VDI mode is designed for

measuring retrograde conduction with the IEGM and/or the marker

function. Retrograde conduction time can be determined directly on

the programmer, or on an additional ECG recorder, as the length of

time between a ventricular pace or sense event and the subsequent

atrial sense event.

OFF Mode

In the OFF mode, pacing pulses are not delivered, except when used

with external pulse control. Without external pulse control, the OFF

mode is used for detection and morphological evaluation of the

intrinsic rhythm. With external pulse control, the OFF mode is used for

electrophysiologic studies and to combat tachycardia. The OFF mode

is only programmable as a temporary program. The pulse and control

parameters remain adjustable in the OFF mode. With the use of the

external pulse control function, the programmer triggers pacing pulses

and sensed events can be transmitted to the programmer. Note that

sensing is limited by the refractory period, whereas pacing is not.

Magnet Effect

Placing a magnet (or the programming wand) over the pacemaker

causes the built-in magnetic switch in the pacemaker to close. The

pacemaker response to magnet application is adjustable.

Note: The following functions are deactivated by magnet

application: