Title Apex Locators Do Not Interfere with Cardiac Implantable Electric Device (CIED) Function
Clinical Question For patients with cardiac implantable electric devices (CIEDs), do apex locators interfere with CIED function?
Clinical Bottom Line Cardiovascular Implantable Electronic Devices (CIEDs) rely on electrical impulses to regulate and sustain a healthy heart rhythm. Any interference with these devices could place the patient at risk. Evidence from two systematic reviews and a cohort study showed that apex locators can produce noise but does not disturb CIED function.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
32852847Niu /202018 studies/ 78 patientsSystematic review of randomized trials
Key resultsIn vitro studies showed that the electromagnetic interference (EMI) was detected when the sensitivity of CIEDs was set at high and when the distance from the electronic apex locator (EAL) to the implantable cardioverter defibrillator (ICD) was extremely close (≤2 cm or 15 cm). In vivo studies showed that EMI was detected in 2 out of 5 EALs tested in some patients with CIEDs.
30458679AlRahabi / 20197 studies/ 39 patientsSystematic review of randomized trials
Key resultsFour out of five in vitro studies showed no EMI from EALs on the implantable electronic devices and one out of the five studies showed that there was EMI but the implantable electronic device function was not altered. One in vivo study showed that EALs did not interfere with the CIEDs, but another showed that EALs can cause background noise or pauses in CIEDs. The limitation of the in vivo studies is that they used small sample sizes and because of the small sizes used, it showed significant interference.
29972599Conde-Mir/201866 PatientsProspective Cohort Study
Key resultsEALs did not affect CIED function in any of the patients. Only noise from EALs was recorded on the electrocardiogram in 2 of 66 (3.3%) patients. EALs do not interfere with pacemaker function.
Evidence Search Electronic Apex locator AND (implantable cardioverter defibrillation or pacemaker)
Comments on
The Evidence
In the Niu study the close distance between the EAL and the CIED as well as increased sensitivity of the pacemaker caused EMI in vitro. However, these settings are not clinically applicable, and in vivo studies corroborated that by showing no interference with CIED function. In AlRahabi study, the majority of the in vitro studies showed no interference between the EALs and CIED function. Only one in vivo study showed interference, but it was temporary and did not cause any permanent damage. Furthermore, this study had a very small sample size. Finally, the Conde-Mir study showed that EALs caused noise in the electrocardiograms of only 3.3% of the patients without disturbing the function. EALs are safe to use with patients with CIEDs. The greatest limitation with the systematic reviews is the lack of meta analyses.
Applicability This topic is applicable for dental practitioners performing endodontic treatment. Apex locators are safe to use on patients with cardiac implantable electric devices (CIED).
Specialty (Endodontics) (General Dentistry)
Keywords Electronic Apex locator, pacemaker, cardiac implantable electric devices
ID# 3548
Date of submission 10/25/2023
E-mail Ghaben@livemail.uthscsa.edu
Author Issam Ghaben DMD
Co-author(s) Alexandra Shepherd DDS MPH
Co-author(s) e-mail shepherda@livemail.uthscsa.edu
Faculty mentor
Faculty mentor e-mail
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available