An active medical device, comprising: - means for delivering electric stimulation pulses applied to electrodes adapted to be implanted in at least one heart cavity of a patient; - means for collecting the electric activity of the heart, comprising means for producing at least two distinct time components ( Vbip, Vuni) based on two distinct endocavitary electrogram EGM signals collected concurrently; and - capture test means, for detecting the occurrence of a depolarization wave induced by the stimulation of the cavity over at least one stimulated cycle, such capture test means comprising: · means for determining a non-time 2D characteristic representative of the cardiac cycle to be analysed, based on the variations of one of the time components ( Vuni) as a function of the other ( Vbip); and · discriminating means, for determining the presence or the absence of a capture by analysing the non-time 2D characteristic, characterized in that the discriminating means comprise: means for the topological analysis of the distribution of the points of said non-time 2D characteristic with respect to a predetermined domain defined in a reference system corresponding to the two time components space, for: · determining, based on the position of said points inside or outside said domain, whether the non-time 2D characteristic is included or not in said domain, and · deciding i) the absence of capture in the first case and ii) the presence of a capture in the second case. - means for delivering electric stimulation pulses applied to electrodes adapted to be implanted in at least one heart cavity of a patient; - means for collecting the electric activity of the heart, comprising means for producing at least two distinct time components ( Vbip, Vuni) based on two distinct endocavitary electrogram EGM signals collected concurrently; and - capture test means, for detecting the occurrence of a depolarization wave induced by the stimulation of the cavity over at least one stimulated cycle, such capture test means comprising: · means for determining a non-time 2D characteristic representative of the cardiac cycle to be analysed, based on the variations of one of the time components ( Vuni) as a function of the other ( Vbip); and · discriminating means, for determining the presence or the absence of a capture by analysing the non-time 2D characteristic, · means for determining a non-time 2D characteristic representative of the cardiac cycle to be analysed, based on the variations of one of the time components ( Vuni) as a function of the other ( Vbip); and · discriminating means, for determining the presence or the absence of a capture by analysing the non-time 2D characteristic, means for the topological analysis of the distribution of the points of said non-time 2D characteristic with respect to a predetermined domain defined in a reference system corresponding to the two time components space, for: · determining, based on the position of said points inside or outside said domain, whether the non-time 2D characteristic is included or not in said domain, and · deciding i) the absence of capture in the first case and ii) the presence of a capture in the second case. · determining, based on the position of said points inside or outside said domain, whether the non-time 2D characteristic is included or not in said domain, and · deciding i) the absence of capture in the first case and ii) the presence of a capture in the second case.