User's Manual

Pacing and Sensing Functions

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Pacing and Sensing Functions

Pulse Amplitude and Pulse Width

In dual-chamber systems, the pulse amplitude and the pulse width are

independently programmable for the atrium and the ventricle.

The BIOTRONIK PAC ("Pulse Amplitude Control") system keeps all

pulse amplitudes below 8.4 V constant during the entire service time of

the pacemaker.

This means that the pacing safety margin is maintained even when the

battery voltage drops. The pulse widths also stay constant during the

entire service time of the pacemaker.

Note: If a pulse amplitude of 7.2 V or higher is

programmed and high pacing rates are attained,

output amplitudes may differ from the

programmed values, as in this case the amplitude

control may not have enough time for an exact

adjustment.

Sensitivity

The "sensitivity" parameter is used to set the pacemaker's sensing

threshold for intracardiac signals. The lower you set the value to be,

the higher the sensitivity.

When the sensitivity is high, there is a risk of the pacemaker being

inhibited by interference signals.

If bipolar leads are used, this risk can be reduced by programming the

pacemaker for bipolar sensing. In the case of high ventricular

sensitivity values, particular attention should be paid to the possibility

of ventricular pacing being inhibited by the atrial pulse (a phenomenon

known as crosstalk). Please see the "Ventricular Blanking Period" and

"AV Safety Delay" sections for more information.

Note: The sensitivity should be programmed to less than

0.5 mV only when sensing is bipolar.