Endocardial pacing has experienced a tremendous evolution since the 1960s. A lot of challenges associated with pacemaker and ICD devices have already been successfully targeted. However, a relevant number of problems have not been solved to date. Not all patients with accepted indication for biventricular pacing have benefited from cardiac resynchronisation therapy (CRT) despite extensive efforts to reduce the rate of non-responders. Current strategies to optimize lead position, multipolar left-ventricular (LV) pacing leads, new strategies to gain access to the left-ventricle (atrial transseptal or ventricular transseptal access) or alternative right-ventricular (septal, His bundle pacing) pacing sites, and “leadless” LV pacing have the potential to increase response to device-based heart-failure treatment. The opportunity of pacemaker and ICD remote monitoring led to relevant improvements in therapy management by timely detection of events requiring medical or invasive interventions (e.g., external cardioversion of atrial fibrillation, increasing effective biventricular pacing, catheter ablation of ventricular tachycardias, or changes in heart-failure medication). Two completely endocardial leadless “all-in-one” pacemaker systems recently became available. Besides these innovations, new “synergistic” therapy concepts combining catheter ablation and device therapy proved to affect clinical endpoints (e.g., ATAAC study and CASTLE-AF study).