A transvenous cardioversion lead system capable of delivering electrical energy to cardiac tissue is provided. Lead system comprises an inner conductor surrounded by an insulative layer which, in turn, is surrounded by a second conductor mounted coaxially with the inner conductor. At least a portion of the second conductor is surrounded by an outer conductive sheath formed from a suitable material having an non-abrasive affect. This prevents damage to cardiac tissue during normal transvenous operating position while at the same time preventing thrombogenesis on the lead surface.