Implantable cardiac pacemakers and defibrillators have greatly decreased the morbidity and mortality rates associated with cardiac arrhythmias. Increasing numbers of people are receiving these devices as the procedures for implantation and device technology improve; as a result, increasing numbers of devices are at risk for infection. The cumulative risk of pacemaker- and defibrillator-related infections after implantation has been estimated to be between 1% and 19% over the lifetime of the device. Infection of these implantable devices is associated with excess morbidity, including prolonged hospital stays and mortality rates as high as 30% in one series.
The first single-chamber permanent pacemakers were introduced for clinical use in the late 1950s. Today, it is estimated that more than 1 million people in the United States have permanent pacemakers. The pacemaker itself consists of a generator, placed below the pectoral muscle, that serves as the power source. An electrical stimulus from the generator travels through an insulated electrical conductor to the electrodes, which deliver the impulse to the endocardium or epicardial surface.
Early implantable cardioverter defibrillator devices (ICDs) required surgical placement of epicardial defibrillation patches, which was facilitated by sternotomy, lateral thoracotomy, or subxiphoid approach. Since 1988, transvenous placement of endocardial coils, similar to pacemakers, has become routine practice. In addition, generator packs have become smaller, allowing for pectoral placement as opposed to the traditional abdominal placement of larger, older generators.