The first line corresponds to lead I with the superimposed markers, the second line to the atrial EGM and the last line to lead III with the superimposed intervals;

1. repetition of AP-VP-AR intervals; the atrial EGM reveals the absence of atrial capture; ventricular capture is effective and is followed by atrial retrograde conduction; this conduction time is relatively short and atrial activity is sensed in the refractory period and therefore does not induce AV delay or ventricular pacing;
2. occurrence of a possible atrial extrasystole or sinus activity, the VP-AR delay being shorter; it is also possible that the same retrograde atrial activity is sensed earlier (variable sensing delay time as a function of respiration for example);
3. on this beat, the delay between VP and atrial sensing is prolonged; the atrial activity is no longer in the refractory period, is labeled AS, induces an AV delay and ventricular pacing;
4. triggering of a PMT; the tachycardia rate (120 beats/minute) signifies that the retrograde conduction is slowed down comparatively to the beginning of the tracing; the atrial activities are no longer in the refractory period; the tachycardia rate is slower than the maximal tracking rate and corresponds to the sum of AV delay + retrograde conduction delay;
5. triggering of the PMT interruption algorithm; prolongation of the refractory period on a beat; retrograde atrial activity falls within this refractory period;
6. atrioventricular pacing with short AV delay (NCAP functioning); the EGM shows the absence of capture and retrograde conduction; the EGM allows eliminating sinus or atrial tachycardia, this atrial activity being directly related to the occurrence of the previous VP;
7. new PMT; note that the interruption algorithm only restarts after 90 seconds explaining the persistence of the tachycardia.