Are leadless pacemakers a niche or the future of device therapy?

P acemakers were developed in the 1950s primarily to treat life-threatening transient heart block after cardiac surgery. These were large external devices connected to epicardial electrodes placed surgically. Although life-sustaining, these devices were plagued by many problems including short battery life, lead failures, and infections, due in part to externalization of part of the system (1). Interestingly, many of these same issues are present today with most left ventricular assist devices, which also are life-sustaining therapies. With advances in technology, size was reduced significantly to allow for the first implantable pacemaker in Sweden in 1958. It was more than 50 years ago, in the early 1960s, that transvenous leads were developed and first used with implantable devices by Parsonnet et al. (2). These early pacemakers had very limited functionality and only performed asynchronous pacing. Rapid advances were made with programmable features, including rate and output, to allow noninvasive communication with devices and improved battery technology to extend pulse generator longevity beyond the approximate 1-year life span of very early devices. Many of the improvements in pacing technology over the past 5 decades are incremental, but some have certainly been game-changing or revolutionary advances, including dual-chamber pacing to allow maintenance of atrioventricular synchrony, rate responsive pacing, and cardiac resynchronization therapy, with or without defibrillation backup