Emerging Technologies in Electrophysiology: From Single-Chamber to Biventricular Leadless Pacemakers

Transvenous pacemakers have been shown to improve quality of life and mortality in patients with bradycardia and cardiac conduction blocks. However, they possess inevitable drawbacks as they have a relatively high incidence of lead and device pocket-related complications. Therefore, leadless pacemakers have emerged as a solution to reduce the complications seen with conventional pacemakers. However, there have been no clinical trials to date comparing transvenous to leadless pacemakers.

Currently, the Micra™ transcatheter pacing system or AV device has been approved for commercial use worldwide but is limited to single-chamber pacing with single- or dual-chamber sensing. Although the leadless pacemaker Nanostim™ was initially promising, it has been recalled due to concerns of battery failures and is no longer approved in Europe. In addition, the lack of defibrillation capabilities with leadless pacemakers has been a limiting factor; therefore, a leadless pacemaker with the already approved subcutaneous cardioverter-defibrillator system is currently being studied in humans. Moreover, the WiSE cardiac resynchronization therapy (CRT) device has been approved in Europe, with the capabilities for leadless CRT in patients with unsuitable coronary sinus anatomy. Furthermore, retrieval of leadless pacemakers has been an area of concern; however, clinic data have signaled toward safe extraction of these devices with minimal complications.

This review will encompass the current literature regarding clinical safety and outcomes of these novel leadless pacemakers and discuss the evolving technologies in the field of cardiac pacing.