Comparative studies of “state of the art” and presently used clinical cardiac pacemaker electrodes

Abstract

Two commonly used clinical cardiac pacemaker leads were compared with two “state of the art” electrode systems. Energy requirements were determined by direct measurement of threshold current and voltage needs, including polarization losses, and the differences in electrode performance were explained by consideration of a multiplicity of previously studied design parameters. The differential current density lead is theoretically optimal and, in short-term studies, required the least threshold energy. However, the practical considerations of ease of placement and questionable long-term stability preclude its clinical use at present. The ball-tip electrode requires somewhat greater threshold energy than the differential current density electrode but very significantly less energy than any of the standard clinical leads in common use. Transvenous insertion is facilitated, and stability problems have not been encountered in a preliminary clinical test of over 1 year's duration. The high current density ball-tip lead is the logical choice for use with a new generation of low-stimulus energy pacemakers, whether nuclear, conventional, solid state, or rechargeable power sources are used.