Patent ID: 8494629

Claim:
An active implantable medical device of the pacemaker, defibrillator and/or resynchronizer type, comprising: means for detection atrial and ventricular events; means for stimulating a ventricle; means for applying to the means for stimulating an atrio-ventricular delay AVD, the AVD being counted from the moment of detection of a spontaneous or stimulated atrial event until a pacing of the ventricle is applied in the absence of a detected spontaneous ventricular event; a hemodynamic sensor delivering a hemodynamic signal representative of a patient's hemodynamic state; means for analyzing the hemodynamic signal and delivering a hemodynamic parameter whose variation with the AVD is a function represented by a sigmoid characteristic; and means for searching for an optimal AVD by analyzing the sigmoid characteristic, wherein the means for searching for an optimal AVD searches without scanning said sigmoid characteristic, and wherein the means for searching for an optimal AVD comprises: means for applying a reference AVD (X c ) and measuring a corresponding hemodynamic parameter (Y 3 ); means for applying at least one left AVD (X L , X LL ), lower in magnitude than the reference AVD, and measuring a corresponding hemodynamic parameter (Y 1 , Y 2 ); means for applying at least one right AVD (X R , X RR ), greater in magnitude than the reference AVD, and measuring a corresponding hemodynamic parameter (Y 4 , Y 5 ); means for evaluating the second derivative of said function at the respective points (X C , Y 3 ; X L , Y 2 , X R , Y 4 ) of the characteristic corresponding to the reference AVD to the left AVD and to the right AVD; means for estimating, from the values of the evaluated second derivatives, a position of an intermediate point of the characteristic for which the second derivative has a minimal value; and means for determining the corresponding AVD for the intermediate point as the optimal AVD.