Abstract

Dermoscopy is currently used as an auxiliary tool in general dermatology. Since some commercially available dermoscopes have built-in magnets, electromagnetic interference (EMI) may occur when examining cardiac implantable electronic devices (CIED) patients. The aim of the study was to create maps of electromagnetic fields defining a safe distance in terms of EMI. The study was performed in laboratory conditions using measuring equipment specially designed for this purpose. The following dermoscopes have been tested: Illuco IDS-1100, Visiomed Luminis, Visiomed Luminis 2, Heine NC2 with and without a contact plate, DermLite DL4, and DermLite Handyscope. Measurements were made for the following set of lift-off distances: 5, 10, 20, 30, 40, 50, and 150 mm. Each 2D scan consisted of 10-line scans shifted from each other by 10 mm. The strength of the magnetic field decreased with the distance from the faceplate. The distribution of the magnetic field differed depending on the position of the magnets. The highest magnetic field was recorded in the center of the Heine NC2 faceplate (up to 8 mT). In most cases, at a distance of 10 mm, the magnetic field strength was measured below 1 mT, with the exception of Heine NC2 and Heine NC2 with a contact plate. All tested dermoscopes generated a magnetic field of <1 mT at the distance of 20 mm. The use of dermoscopes with built-in magnets may affect the functioning of CIEDs, and the impact may vary depending on the type of dermoscope.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8551606/

The post Electromagnetic Field Associated With Dermoscope Magnets May Affect the Safety of Cardiac Implanted Electronic Devices Patients appeared first on EMFSA.

Abstract

Prior to ventricular tachycardia ablation, this patient’s cardiac implantable electronic device (CIED) was temporarily programmed to backup pacing mode with tachycardia therapies disabled. During radiofrequency energy delivery, the patient developed ventricular fibrillation requiring emergent cardioversion. Electrogram interrogation showed that the CIED switched to noise reversion mode during ablation. The consequent asynchronous pacing resulted in a paced QRS landing on an intrinsic T wave, inducing ventricular fibrillation. This serves as an important reminder that asynchronous pacing consequent to CIED oversensing could occur in any procedure that could cause electromagnetic interference such as radiofrequency catheter ablation.

© 2021 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of the Japanese Heart Rhythm Society.

https://pubmed.ncbi.nlm.nih.gov/33850578/

The post Pacemaker-induced ventricular fibrillation during radiofrequency catheter ablation for ventricular tachycardia appeared first on EMFSA.

Abstract

Introduction: : Electromagnetic interference (EMI) of cardiovascular implantable electronic devices (CIED) can lead to malfunctions and pose a danger for implant carriers. The increased use of DC technologies, e.g., in electric mobility, creates more static fields representing an increasing hazard for implant carriers.

Areas covered: : A combination of approaches was used to determine thresholds for EMI by static fields. A literature search was conducted to identify relevant EMI mechanisms and to extract possible thresholds. The literature search revealed four interference mechanisms caused by static magnetic fields and none for static electric fields. Due to the scarce information on motion-induced EMI, numerical simulations were performed to obtain a threshold. The simulation results were evaluated using medical product standards and benchmark tests on commercially available CIEDs. The results show that motion-induced interference should not occur below the activation of the magnetic safety switch (reed switch or Hall-effect sensor, MSS).

Expert opinion: : The determined threshold for motion-induced EMI at 24.8 mT shows that the MSS activation is still the most relevant mechanism that can occur at 0.8 mT. Limit values for the general population do not protect implant carriers from EMI.

https://pubmed.ncbi.nlm.nih.gov/33710950/

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