In vitro interference of Electronic Apex Locator on Implantable Cardiac Pacemaker

Abstract

Introduction: Electronic Apex Locators (EAL) may interfere with Cardiac Pacemakers (PM) by electromangnetic interference (EMI). Objective: To evaluate, in vitro, the EMI caused by EAL on a PM. Methods: Four different EAL (Apex DSP, NovApex N-21, RomiApex A-15, C-ROOT I) had their electrodes immersed in a saline solution at distances of 10, 15, 20, 25 and 30 cm from the electrode of the PM (Medtronic Sensia SEDR01) monitored by telemetry. Results: With 0.2 mV sensitivity, the PM had interference from all 4 EAL, with inhibition, stimulation recycle, and deflagration. With 2mV sensitivity, no interference was observed. Regardless the PM sensitivity, no EAL was able to lead, even at short distances, reversion to asynchronous or deprogramming. Conclusion: When set to maximum sensitivity, the PM suffered interference, although that wouldn’t be a real in vivo situation.