Patent ID: 7366566

Claim:
An active implantable medical device comprising: means for detecting spontaneous atrial and ventricular events; means for ventricular and atrial stimulation; means for operating the device in AAI mode with ventricular detection; means for operating the device in DDD mode; means for mode switching, wherein said means for mode switching further comprises means for controlling switching from AAI mode to DDD mode when at least one of the following conditions, each of which is checked by the means for mode switching, is fulfilled: a) the number of atrial events followed by a ventricular detection occurring after a delay longer than a first reference duration exceeds a first predetermined number; b) the number of atrial events not followed by a ventricular detection exceeds a second predetermined number among a third given number of consecutive atrial events; c) the number of consecutive atrial events not followed by a ventricular detection exceeds a fourth predetermined number; and d) the interval separating two ventricular events exceeds a second reference duration; and wherein said means for mode switching further comprises means for controlling the return from the DDD pacing mode to AAI pacing mode according to a criteria; means for state detecting, further comprising means for diagnosing a temporary specific state of a patient carrying the device, including a phase of suspicion of disorder of the atrial rate of the patient and at least one of a phase of effort and a phase of sleep of the patient; and wherein the mode switching means further comprises means for suspending, when said means for state detecting diagnoses a phase of suspicion of disorder of the atrial rate of the patient, the checking of the conditions a) to c), while maintaining the checking of the condition d), for a length of time at least equal to a duration of the phase of suspicion of disorder of the atrial rate of the patient.