Arandomized in vitro evaluation of transient and permanent cardiac implantable electronic device malfunctions following direct exposure up to 10 Gy.

Abstract

High-dose 6‑MV radiotherapy may cause cardiac implantable electronic devices (CIEDs) to malfunction. To assess CIED malfunctions resulting from direct exposure up to 10 Gy, 100 pacemakers (PMs) and 40implantable cardioverter-defibrillators (ICDs) were evaluated. CIEDs underwent baseline interrogation. In ICDs, antitachycardia therapies were disabled via the programmer while the detection windows were left enabled. Acomputed tomography (CT) scan was performed to build the corresponding treatment plan. CIEDs were "blinded" and randomized to receive single doses of either 2, 5, or, 10 Gy via a6-MV linear accelerator (linac) in awater phantom. Twenty-two wireless telemetry-enabled CIEDs underwent areal-time session, and their function was recorded by the video camera in the bunker. The CIEDs were interrogated after exposure and once monthly for 6months. During exposure, regardless of dose, 90.9% of the CIEDs recorded electromagnetic interference, with 6ICDs (27.3%) reporting pacing inhibition and inappropriate arrhythmia detections. After exposure, abackup reset was observed in 1PM (0.7% overall, 1% among PMs), while 7PMs (5% overall, 7% among PMs) reported battery issues (overall immediate malfunction rate was 5.7%). During follow-up, 4PMs (2.9% overall; 4% among PMs) and 1ICD (0.7% overall; 2.5% among ICDs) reported abnormal battery depletion, and 1PM (0.7% overall; 1% among PMs) reported abackup reset (overall late malfunction rate was 4.3%). Apart from transient electromagnetic interference, last-generation CIEDs withstood direct 6‑MV exposure up to 10 Gy. Permanent battery or software errors occurred immediately or later only in less recent CIEDs.