Clin Res Cardiol (2021). 10.1007/s00392-021-01933-9

VVI 100 forever? – A case report of sudden battery depletion during device interrogation of a leadless pacemaker
S. Suhail Arain1, S. Biewener1, P. Nagel1, V. Tscholl1, U. Landmesser1, P. Attanasio1, M. Huemer1
1CC 11: Med. Klinik für Kardiologie, Charité - Universitätsmedizin Berlin, Berlin;

Background

Leadless cardiac pacemaker (LCP) therapy is an alternative to conventional transvenous pacemaker therapy for patients with an indication for single-chamber right-ventricular pacing. Reports on loss of telemetry and pacing output because of battery failure are a known problem in the Nanostim™ LPC which lead to a global stop to Nanostim™ implants.

Case summary

A 30-year-old female patient presented to the device clinic for routine check-up of her Nanostim™ LPC which was implanted in 2015 for recurrent cardioinhibitory syncope with sinus arrest of up to 20 seconds. Since the implantation no syncope had recurred. At the time of the interrogation the patient was in sinus rhythm with a heart rate of 80 bpm. Programming was VVI 50 with a ventricular pacing rate of 0%. Estimated time to RRT > 25 years, battery voltage 3.25 V, load impedance 520 ohms and R-wave amplitude > 12 mV.  Capture threshold testing was not possible as only intermittent pacing impulses were generated. In order to evaluate whether pacing is possible the device was programmed to VVI 100, what lead to adequate continuous ventricular pacing at rate of 100bpm. When trying to reprogram to VVI 50 the alert “Loss of telemetry detected” popped up and no more changes in settings were possible. The battery voltage and estimated time to RRT were not retrievable anymore. The values for load impedance varied from <250 ohms to >2000 ohms and intermittent loss of detection of EGMs signals in the marker channel was observed.

Abbott support engineers confirmed the case of sudden battery depletion with loss of telemetry and no option of changing the programming or even turning off the pacemaker completely. Subsequently the young otherwise healthy patient was being paced unnecessarily with VVI 100 until complete depletion of battery. Surgical device explantation was suggested. As an alternative repetitive measuring of the impedance could be tried because it is energy consuming and may expedite battery depletion. After an estimated ~20 impedance measurements complete battery depletion and stopping of pacing was achieved.

Conclusion

This is a case of unforeseen sudden battery depletion while interrogating the Nanostim™ triggered by reprogramming the device. Due to the risk of irreversibility, programming the device to higher heart rates or VOO mode should be avoided.



https://dgk.org/kongress_programme/ht2021/P153.htm