Estella Pulse Generators - BIOTRONIK USA - News

66 Estella Pulse Generators Technical ManualConfirmationWhen the suspicion criteria have been met, the AV delay is increased bythe programmed far-field protection interval (up to a maximum of 300ms. If an atrial event is detected within the AV delay and the detectedatrial rate is less than the programmed Mode Switch Detection rate, a2:1 Lock-In is confirmed.Otherwise, 2:1 Lock-In is not confirmed, and the AV delay is graduallydecreased to the programmed value. The 2:1 Lock-In Managementfeature is suspended for 120 seconds.TerminationThe pulse generator will immediately mode switch to a non-atrialtracking mode (e.g., DDDR to DDIR) when the confirmation criteria havebeen met, and then the 2:1 Lock-In Management feature is suspendeduntil the pulse generator mode switches back to the programmedpacing mode.In order to optimize the programmability of the 2:1 Lock-In Managementfeature, the far field protection period is programmable to allow thephysician to ensure that the protection period is sufficient to recognizecases where a 2:1 lock-in is likely to occur. Refer to Section 7.5.5 forrecommendations for programming the far field protection period inconjunction with the 2:1 Lock-In Management feature.7.9 Atrial Upper RateThe atrial upper rate (AUR) prevents atrial pacing from occurring in thevulnerable phase after an atrial sensed event during the PMT protectioninterval, and ensures that the next atrial paced event occurs after theheart’s natural atrial refractory period.To avoid this, an atrial upper rate of 240 ppm (atrial upper interval (AUI),250 ms) is started after a PMT-As.The next Ap can only be emitted after the expiration of the AUI. Whenthere are high sensor rates, the atrial pacing is shifted.NOTE:Right atrial pacing does not occur when mode switching is activated,and when the atrial upper rate is activated in DDI mode at the end ofthe sensor or basic interval.7.10 Atrial Overdrive Pacing (Overdrive Mode)The atrial pacing rate increases after each atrial sensed event that isnot classified as an atrial extrasystole, in an attempt to suppress atrialtachyarrhythmias. The overdrive algorithm triggers atrial overdrive