Cardiac rhythm devices of today and tomorrow

After 50 years of a fundamentally unchanged pacemaker schema-a pulse generator with battery and electronics connects to insulated conductors (leads) that sense and stimulate atrial and/or ventricular myocardium-the basic paradigm of how cardiac tissue is stimulated to treat arrhythmias is dramatically changing. The aim of this chapter is to review pertinent contemporary and emerging pacing technologies and to present concepts and the available clinical evidence evaluating their safety and efficacy. These range from algorithms to extend device longevity and minimize ventricular pacing, to leadless pacemakers and His bundle pacing, which eliminate leads or leverage the heart’s own conductive tissues to effectively distribute stimulation, respectively. Basic pacemaker functions, sensing and pacing, are aptly discussed elsewhere and are the not the focus of this chapter. Rather, we will review more recent advances of the components of pacing systems as well as of the algorithms that govern their function. Implantable cardioverters defibrillators and cardiac resynchronization therapy systems are discussed at length in other chapters of this book and will therefore not be included in the scope of this chapter.