User's Manual

Rate Adaptation

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The pacemakers are equipped with an accelerometer that is integrated

into the hybrid circuit. This sensor produces an electric signal that is

constantly processed by analog and digital signal facilities. If a rate-

adaptive mode is programmed, then this effects an adjusted increase

of the basic rate, depending on the exertion level of the patient. With

the sensor being integrated in the hybrid circuit, it is not sensitive to

static pressure on the pacemaker housing.

The sensing and inhibition function remains activated during sensor-

controlled operation. In case of high pacing rates, however, the

refractory periods may cover a majority of the basic interval, resulting

in asynchronous operation.

Convenient diagnostics features allow you to quickly set individual and

optimal rate adaptation for the patient (see the section on “Follow-up

Options” for more details).

Physiologic Rate Adaptation (The CLS Feature)

How Closed Loop Stimulation Works

The contraction dynamics of the myocardium vary depending on the

patient's exertion. These changes are characteristic, allowing Closed

Loop Stimulation to determine a pacing rate that is patient-specific

and physiologically appropriate. This also applies to times when the

patient is emotionally stressed.