Detection and confirmation of cross-sensing phenomenon in active implantable medical devices

摘要

An active implantable medical device, especially of a cardiac pacemaker, defibrillator and/or cardiovertor type, having a dual chamber stimulation function and protection against cross-sensing atrio- ventricular phenomena. Cardiac events, spontaneous or stimulated, are detected in a first cavity, preferably the atrium, and a second cavity is stimulated, preferably the ventricle, The detection and confirmation of cross-sensing is performed by detecting in the atrium a signal coming from a depolarization consecutive to a preceding stimulation of the ventricle, and distinguishing such a signal from a signal resulting from spontaneous activity of the atrium. According to an embodiment, the detection of cross-sensing preferably includes the detection of an activity of the atrial extra-systole type occurring between a ventricular stimulation and a consecutive atrial event, stimulated or spontaneous, in order to determine that the interval of time between the stimulation of the second cavity and the atrial extra-systole type is less than a predetermined duration, and to detect the stability of this interval, preferably by modulating the atrio-ventricular delay (AVD) and to detect the absence of significant modification, with regard to these variations, in a particular time interval in question.