Patent ID: 7349737

Claim:
An active implantable medical device, comprising: circuit means for detecting spontaneous atrial and ventricular events; circuit means for providing ventricular and atrial stimulation, said atrial stimulation having an initial stimulation energy and being an adjustable stimulation energy; and means for suspecting a loss of an atrial detection and loss of an atrial capture, comprising means for determining a sequence of events having one or more of provided stimulations and detected ventricular and atrial events, and means for analyzing said sequence to detect: an absence of ventricular activity post-atrial stimulation, a lengthening, beyond a given limit, of an atrio-ventricular conduction delay over a predetermined number of successive cardiac cycles, an occurrence of an atrial detection consecutive to an atrial stimulation over a predetermined number of successive cardiac cycles, a detection of a ventricular extrasystole, a reduction below a given limit of a delay between an atrial stimulation and a ventricular detection, and a passage from an atrial detection to an atrial stimulation with a concomitant reduction, below a given limit, of a delay between an atrial event and a ventricular detection.