Recent Advances in Pacing and Defibrillation

Most current pacemaker and ICD systems involve placement of lead(s) transvenously into the heart, connected to a pulse generator. Vascular access may be difficult or limited in some patients, and intravascular leads can be associated with multiple complications such as infection, lead malfunction and vascular occlusion. Recent advances in pacing and ICDs include the development of subcutaneous ICDs and leadless pacing. Subcutaneous ICDs do not require a transvenous access or lead, and have become an important option for patients with indications for ICDs who have limited or difficult vascular access or have a significant risk with this approach. In addition, subcutaneous ICDs can be offered as an alternative to transvenous ICDs in certain patients. Leadless pacing is evolving as a new approach to pacing that can avoid or mitigate the issues associated with intravascular leads. Self-powered leadless cardiac pacemakers have been shown to be a safe and feasible option for patients requiring single chamber pacing. In addition, leadless ultrasound-based pacing has been shown to provide effective left ventricular pacing for cardiac resynchronization therapy in conjunction with a traditional transvenous device. Future advances in the technology of leadless pacing will hopefully allow multichamber pacing (and multisite pacing within a chamber) with all the sophistication of current transvenous systems. Perhaps, leadless pacing can even be combined with a subcutaneous ICD in the same patient.