Investigation of safety for electrochemotherapy and irreversible electroporation ablation therapies in patients with cardiac pacemakers

Abstract

Background The effectiveness of electrochemotherapy of tumors (ECT) and of irreversible electroporation ablation (IRE) depends on different mechanisms and delivery protocols. Both therapies exploit the phenomenon of electroporation of the cell membrane achieved by the exposure of the cells to a series of high-voltage electric pulses. Electroporation can be fine-tuned to be either reversible or irreversible, causing the cells to either survive the exposure (in ECT) or not (in IRE), respectively. For treatment of tissues located close to the heart (e.g., in the liver), the safety of electroporation-based therapies is ensured by synchronizing the electric pulses with the electrocardiogram. However, the use of ECT and IRE remains contraindicated for patients with implanted cardiac pacemakers if the treated tissues are located close to the heart or the pacemaker. In this study, two questions are addressed: can the electroporation pulses interfere with the pacemaker; and, can the metallic housing of the pacemaker modify the distribution of electric field in the tissue sufficiently to affect the effectiveness and safety of the therapy? Results The electroporation pulses induced significant changes in the pacemaker ventricular pacing pulse only for the electroporation pulses delivered during the pacing pulse itself. No residual effects were observed on the pacing pulses following the electroporation pulses for all tested experimental conditions. The results of numerical modeling indicate that the presence of metal-encased pacemaker in immediate vicinity of the treatment zone should not impair the intended effectiveness of ECT or IRE even when the casing is in direct contact with one of the active electrodes. Nevertheless, the contact between the casing and the active electrode should be avoided due to significant tissue heating at the site of the other active electrode for the IRE protocol and may cause the pulse generator to fail to deliver the pulses due to excessive current draw. Conclusions The observed effects of electroporation pulses delivered in close vicinity of the pacemaker or its electrodes do not indicate adverse consequences for either the function of the pacemaker or the treatment outcome. These findings should contribute to making electroporation-based treatments accessible also to patients with implanted cardiac pacemakers.

Pulsed field ablation-based pulmonary vein isolation in atrial fibrillation patients with cardiac implantable electronic devices: practical approach and device interrogation (PFA in CIEDs)

“…Prior study of high-voltage electroporation pulses used in other fields such as oncology has been performed in patients with CEIDs without any effect on the device parameters [16]. According to our ablation protocol, PFA should not be performed with direct contact to the CIEDs or other devices.…”

The Good and the Bad of Cell Membrane Electroporation

“…85 The factors that can limit the use of ECT include the size of the tumor 89 and difficult accessibility of a tumor by electrodes For safety reasons, ECT is currently contraindicated for patients with cardiac pacemakers and patients on anticoagulant therapy. 3,90…”

Coupled Thermo-Electro-Mechanical Models of Cardiac Ablation at Tissue-Cellular Scales and a Role of Microtubules

“…In cardiology, the pulsed-field ablation has been receiving larger attention as an ablative modality that uses short living, the strong electrical field created around the catheter to create microscopic pores in cell membranes, providing also the basis for electroporation [31]. The latter treatment technology has important implications for cardiac patients and a series of recent studies have been devoted to its various aspects, including the observed effects of electroporation pulses delivered in close vicinity of the cardiac Sundeep Singh and Roderick Melnik pacemaker or its electrodes [32]. Moreover, recent advances in cardiac electrophysiology and related ablation procedures may lead to the development of new biomarkers for patients with heart disease [33].…”