Pacemaker technology: an overview.

Cardiac pacing has evolved considerably over the past 30 years. Early pacemakers were nonprogrammable asynchronous devices which prevented asystole, syncope, and death. The current generation of implantable devices is much more sophisticated. With multiprogrammable features, these devices are intended not only to save life but also to improve the quality of life. This chapter reviews the pacemaker mode-code, indications, electronic circuitry, power sources, and programmable/telemetry features of current devices.