Cardiac pacing leads.

Many of the advances that have been seen in the last decade concerning the functionality, size, and longevity of cardiac pacemakers have been dependent upon concomitant advances in cardiac pacing leads. The most difficult component of a pacing lead to develop has been the insulator. There are many choices for physicians implanting pacing leads: active versus passive fixation, standard impedance versus high impedance and polyurethane versus silicone. The current state of affairs of cardiac pacing leads is quite good in that we have leads that have excellent electrical properties and appear to be more resistant to the hostile environment into which the lead is placed. In spite of this, the goal of a perfect lead remains elusive and there continues to be many challenges in lead design.