A medical device includes a pulse generator and an electrode configured to contact tissue in a body vessel. The medical device includes a lead that includes a lead connector. The lead connector connects a pulse generator with an electrode via a conductive path. An electrode switch is electrically connected between the lead conductor and the electrode. The electrode switch includes an open state preventing the conductive path between the lead and the electrode. The electrode switch includes a closed state establishing the conductive path between the lead and the electrode when a voltage is applied across the electrode switch that exceeds a threshold voltage. The electrode switch in the open state electrically shields the electrode from electromagnetic radiation and induced voltages during magnetic resonance imaging.