Adjusting the maximum ventricular stimulation frequency according to the hemodynamic state of the patient in an active implantable medical device

摘要

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_max), the rate of delivery of the stimulation pulses, measuring an intracardiac bio-impedance (Z_n, Z_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_n, d_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_max) according to the variation of the cardiac flow thus evaluated.