Minute ventilation dependent rate responsive pacer

摘要

An electronic circuit included in a pacer detects the impedance between two electrodes connected to it and made up by the conducting part of the pacer case (B) and by an auxiliary subcutaneous lead placed in the chest or by an electrode placed on the insulating part (C) of the case itself. The changing geometry of the chest, due to pulmonary ventilation, determines the impedance variations. The electronic circuit, by processing the impedance signal is able to automatically adjust the stimulation rate of the ventricle and/or of the atrium between minimum and maximum preset values according to the activity levels of the patient.