Patent ID: 7203544

Claim:
An active implantable medical device, in particular a cardiac pacemaker, defibrillator, cardiovertor or multisite device, comprising: a terminal having a receptacle for receiving an intracardiac electrode of an implanted probe, said probe having a distal end located in a first cardiac cavity; at least one circuit for delivering a stimulation pulse to said terminal; means for applying a stimulation pulse to said terminal for delivery to said first cardiac cavity; a discharging circuit coupled to said terminal having a switch operable to short-circuit for a discharge period said terminal; at least one circuit for detecting at said terminal electronic signals corresponding to spontaneous potential appearing in said first cardiac cavity, including an amplifier having an input coupled to said terminal and an output, and a blanking circuit having a switch able to temporarily uncouple the terminal from the amplifier input; and a sequencer control circuit to, successively within the same cardiac cycle: activate the discharging circuit in response to an application of the stimulation pulse, throughout the discharge period, and activate the blanking circuit for a first time throughout a detected stimulation pulse, activate the discharging circuit with a delay after the application of the stimulation pulse, inhibit the blanking circuit for a listening period, said listening period comprising at least a part of the said delay, wherein during this period of listening, the amplifier detects at said terminal, electric signals corresponding to spontaneous post-stimulation potentials in the first cavity; and activate the blanking circuit a second time after the listening period, throughout said discharge period.