Over the past quarter of a century notable advances have been made in the performance and reliability of the electronic systems that are used to provide cardiac pacing. Problems remain, however, and to seek solutions to some of these an International Symposium on Pacemaker Leads and electrodes was held from the 5th to the 7th September 1984 at the Catholic University of Leuven, Belgium. Now fifty-nine of the invited lectures and contributed papers have been published in the Proceedings which provide a clear picture of the present state of the art. They also serve as a useful introductory guide to the subject.

Pacemaker leads have two main functions: to conduct electrical pulses to the heart and to sense intra-cardiac signals and transmit these to the pulse generator. The performance of the electrode at its interface with the cardiac tissue is crucial to the satisfactory functioning of the pacing system and many of the papers considered the size and geometrical configuration of the electrode tip, the material of construction and the condition of the surface.

On account of their biocompatibility and corrosion resistance, coupled with their electrical properties, platinum and platinum alloys became the preferred materials for electrodes during the 1970s, although carbons, titanium and multi-component base metal alloys also find application. In order to improve further the results obtained with these materials, engineering modifications to the electrodes continue. In earlier years, lead dislodgement was a problem but now this may be overcome by the use of hooked, screw-in or tined electrode tips. To improve sensing amplitudes and achieve the lowest possible threshold values a variety of electrodes have been constructed. Platinum tips may be in the form of ball-tips, discs, half domes or rings, and the surfaces may be polished, etched, porous or even laser drilled.

Amply supported by references, this book is likely to become a standard source of information on pacemaker leads. Collaboration between people from many different disciplines has enabled cardiac pacing to achieve very considerable success. This evolution must be continued, and therefore these Proceedings are commended to the readers of this journal.