Investigation of Radiofrequency-induced Heating of Abandoned Cardiac Lead Wire with Conductive Caps of Different Electrical Conductivities

Motivation: To reduce radiofrequency (RF)-induced heating of abandoned implantable cardiac leads equipped with plastic caps, which remarkably increase heat generation around the lead tip. Goal(s): RF-induced heating with various electrical property of the cap was investigated to find optimal condition. Approach: Tissue heating around the lead wire with caps of electrical conductivity ranging over 10-6 to 10+6 S/m were compared in the ASTM phantom model by FDTD simulation, and validated by experiments. Results: Tissue heating around the lead tip clearly decreased and became similar to the uncapped case, when the conductivity was higher than 10-1 S/m, which was approximately the same as the media. Impact: Simulations and experiments on abandoned cardiac leads revealed that the "electrically conductive cap" dramatically reduces RF-induced heating around the lead tip. Such cap may protect the lead from body fluid infiltration into the insulation material while also contribute to MR-safety.