Cardiac Pacemaker Exposed to Electroporation Pulses - An Ex Vivo Study

摘要

Electrochemotherapy (ECT) consists of administration of a chemo-therapeutic drug followed by local application of high-voltage electroporation (EP) pulses and is a well-proven method for treatment of various types of tumors. However, as a precaution ECT of deep-seated internal tumors is contraindicated in patients with implanted cardiac pacemakers. To address this limitation a functioning pacemaker programmed in asynchronous D00 mode with the ventricular and atrial leads connected was exposed to EP pulses in a conductive medium mimicking the conditions encountered in clinical setting. EP pulses were generated by the Cliniporator Vitae device and delivered via electrodes for clinical ECT. Application of EP pulses was synchronized with different phases of the pacing cycle, including the potentially most vulnerable phase, the pacing pulse itself. The effects on pacemaker operation were investigated by recording the voltages between the cathode and the anode of the bipolar ventricular lead. EP pulses induced large artefacts far exceeding the amplitude of the pacing pulse itself. This was followed by transiently disrupted shape of the remaining portion of the pacing pulse. However, all effects were strictly limited to this single pacing pulse. No effects at all were observed in subsequent pacing pulses. The pacemaker and its function remained completely immune to electroporation pulses delivered outside the pacing pulse itself.