Patent ID: 6181968
Filing Date: 2001-01-30
Classification: A61N

Abstract:
An active implantable medical device, particularly a pacemaker, defibrillator and/or cardiovertor of the multisite type, having a capture threshold, in which electrodes are to be placed at at least two neighboring cardiac sites selected from among a right and left ventricular sites, a right and left atrial sites, and a right and left ventricular and atrial sites, these electrodes being connected to a cardiac signal sensing circuit to detect a potential of depolarization on a corresponding site including a capture, and to a stimulation circuit to apply, if necessary, a stimulation impulse on said corresponding site, said device having a capture threshold corresponding to a minimal amplitude level allowing the sensing, on a considered site, of a detected depolarization following a preceding stimulation impulse, comprising:means for adjusting an amplitude of stimulation in relation to a capture threshold for each cardiac site, said adjusting being responsive to the detection of a capture to adjust said stimulation threshold and the non detection of a capture to fix said threshold; andmeans for fixing a total refractory period (""PRT"") having a duration comprising an absolute refractory period (""PRA"") and a relative refractory period (""PRR""), the absolute refractory period corresponding to a time during which all detection is inhibited;wherein said cardiac signal sensing circuit senses a potential of said at least two neighboring cardiac sites detects a depolarization potential on at least one of said neighboring cardiac sites during the relative refractory period, and determines in response thereto a state of loss of a capture at said at least one cardiac site.