Patent ID: 7164947

Claim:
A heart stimulator comprising: a stimulation pulse generator that emits stimulation pulses adapted to stimulate a heart of a patient; an impedance measuring unit having at least two measurement electrodes, and adapted to measure an impedance, having a real part and an imaginary part, between said at least two measurement electrodes resulting from volume changes of at least one left chamber of a heart of the patient, said impedance measuring unit emitting an impedance signal corresponding to said impedance; a calculation unit supplied with said impedance signal for calculating, for a predetermined pattern of said stimulation pulses, an average impedance morphology curve from said real part of said impedance signal, and an average morphology curve from said imaginary part of said impedance signal, during a time interval of a plurality of cardiac cycles of the heart; and an analyzer supplied with said average impedance morphology curves for analyzing said average impedance morphology curves to generate a control signal for emission of said stimulation pulses to optimize hemodynamics of the patient.