| 摘要 |
A heart controlling apparatus for controlling a mechanical function of the heart, the device comprising impedance measuring means (3) for measuring a transvalvular impedance measurement made between an atrium electrode (19,21) and a ventricle electrode (23) of a standard implanted electro-catheter to provide information indicative of the mechanical state of the heart. <??>Further, calculating means (5) are provided for using determined minimum and maximum impedance measurements to provide calculated data representative of at least one of: an impedance measurement cycle time indicative of information about the operation of the heart, the time between the minimum impedance and the following maximum impedance indicative of the time the valve is closed, and the rate of change of impedance between the minimum value and the subsequent maximum value in a cycle indicative of the contractility of the heart. Moreover, control means (181,183;385,390) are provided for controlling a mechanical function of the heart in accordance with the calculated data, for example, to control the pacing rate of a rate responsive pacemaker, stimulation intensity self adjust or pacing mode switching. Other uses are also possible in defibrillators. <IMAGE>
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