[Leadless pacemakers and subcutaneously implantable cardioverter defibrillators]

Although pacemakers and implantable defibrillators have become the standard treatment of bradycardic and tachycardic arrhythmias, long-term complications caused by the transvenously inserted pacing and defibrillation leads, such as electrode fracture, lead infection and tricuspid valve insufficiency are not uncommonly observed. Therefore, leadless pacemakers and purely subcutaneously implantable cardioverter defibrillators (S-ICDs) have been developed in recent years, which are implanted without transvenous electrodes with the aim to reduce long-term complications with these devices; however, currently available leadless pacemakers are limited to single chamber stimulation and S‑ICDs are limited to pure defibrillation without antibradycardic, antitachycardic pacing or cardiac resynchronization capabilities. Thus, these devices cannot yet be used as multichamber pacemakers or defibrillators even though in these circumstances a higher complication rate is to be expected due to the multiple number of transvenous leads. This article summarizes the current state of knowledge on leadless pacemakers and ICDs, discusses the limitations of these devices and provides an outlook into their future development.