Active implantable medical device, especially a pacemaker, defibrillator and/or cardiovertor of the ddd/aai type with effort optimized operation

Abstract

An improved active implantable medical device which detects spontaneous atrial and ventricular events, the presence or the absence of an atrio-ventricular spontaneous conduction, and stimulates the atrium and the ventricle, an automatic mode switching operation as between, e.g., DDD and AAI operating modes, for cardiac pacing, which device also includes an activity sensor to discriminate between phases of effort and rest of the patient, and measures the conduction time separating a spontaneous or stimulated atrial event, and a consecutive corresponding spontaneous ventricular event, and provides for a diagnosis of a good or a bad adaptation of the conduction time during the effort phase of the patient. The diagnosis of a good or bad adaptation is performed by an evaluation, during the effort, of the variation of the conduction time in relation to the variation of the heart rate. When the diagnosis indicates a bad adaptation during the effort, the automatic mode switching operation is deactivated and the device is switched to a DDD operating mode such that the atrio-ventricular delay is reprogrammed with a value shorter than the value programmed before, which operating conditions are maintained until the effort is ended.