Discriminating between tachycardias of ventricular origin and supra entricular origin, methods and apparatus

An active medical device, having means for collecting an electrical activity of a patient's heart, including means for producing at least two distinct temporal components corresponding to two EGM signals of a ventricular electrogram;

• means for detecting a presence of a tachycardia episode in said collected electrical activity;
• and diagnosis means for diagnosing a ventricular tachyarrhythmia including means for discriminating in the detected tachycardias between a Ventricular Tachycardia originated in the ventricles and a Supra-Ventricular Tachycardia originated above the ventricles, wherein the improvement comprises:
• the collecting means further comprising means for producing a first and a second distinct temporal components from said two distinct EGM signals of ventricular electrogram;
• the diagnosis means further comprises means for conducting a bi-dimensional analysis, able to determine, from the variations of one of said first and second temporal components as a function of the other of said first and second temporal components, a 2D characteristic representative of a heart beat;
• and
• discriminator means further comprising means for comparing:
• a first current 2D characteristic, representative of a tachycardia beat (SVT, VT), from said at least two EGM signals collected during a tachycardia episode, with
• a second reference 2D characteristic, representative of a Sinus Rhythm (SR) beat from said two EGM signals, collected from non-tachycardia episodes.