The Microport defibrillator algorithm continually evaluates the criteria explained in the following paragraphs as soon as a ventricular cycle is detected in the Tachy/VF zone. Depending on the combination of criteria defined by the physician, some of these criteria will be taken into account in order to establish a classification (diagnosis) that will need to be maintained in order to lead to a binary result, namely treatment (VT) or no treatment (SVT). It should be remembered that in the VF zone (Fast VT zone included), no discrimination is made for differentiating between SVT and VT. The only criterion used is that of stability, in the Fast VT zone only, and not for the diagnosis, but rather to decide whether or not to administer an ATP prior to the capacitor charge if programmed.