Adjusting the maximum ventricular stimulation frequency according to the
hemodynamic state of the patient in an active implantable medical device.
This device provides for limiting ventricular stimulation to a maximum
frequency (F.sub.max), the rate of delivery of the stimulation pulses,
measuring an intracardiac bio-impedance (Z.sub.n, Z.sub.n+1), and
adjusting the maximum frequency according to the measured intracardiac
bio-impedance. The adjusting process can include evaluating a parameter
representative of the cardiac flow (d.sub.n, d.sub.n+1) utilizing the
intracardiac signal of bio-impedance; controlling a predetermined
variation (X %) of the frequency (f) of delivery of the stimulation
pulses; evaluating the correlative variation (y %) of the cardiac flow;
and adjusting the value of the maximum frequency (F.sub.max) according to
the variation of the cardiac flow thus evaluated.