A heart stimulator

摘要

A heart stimulator for electric stimulation of a patient's heart comprises an impedance measuring unit (21, 28, 30) adapted to measure the impedance (Z) between at least two measurement electrodes (24, 26) intended to be implanted in a patient such that volume changes of at least one of the chambers of the left heart result in changes in the measured impedance. Analysing means (36) are provided for analysing the measured impedance for the control of the stimulation of the heart. A calculation means (34) is provided to calculate an average impedance morphology curve during a time interval of several cardiac cycles. The analysing means are adapted to analyse the average impedance morphology curve for use for the control of the stimulation to optimise the patient hemodynamics. <IMAGE>