Patent ID: 8233981

Claim:
An active implantable medical device of the cardiac stimulation, resynchronization, cardioversion and/or defibrillation type, comprising: means for detecting spontaneous and stimulated atrial events; means for detecting ventricular events; means for calculating an atrio-ventricular delay AVD, said AVD starting on the detection of one of a spontaneous and a stimulated atrial event; an acceleration sensor having an output signal that is an EA signal representative of the movements produced by the contractions of the atrial cavity; means for analyzing the EA signal to identify and isolate in the EA signal an EA 4 component corresponding to the fourth peak of endocardiac acceleration associated to the atrial activity, and means for calculating the value of the AVD based upon the EA 4 component; and means for pacing the ventrical with a low energy stimulation pulse, in response to an expiration of the calculated AVD and in the absence of a detected spontaneous ventricular event, wherein the means for calculating the value of the AVD further comprises means for determining a parameter of the EA 4 component as a function of an end time of the EA 4 component, and calculating the value of the AVD as a function of said determined parameter.