*2.5.1 Traditional single-chamber pacing*

The most known location of the pacing electrode is the tip (apex cavity) of the right ventricle. This solution has been working well for many decades in cardiac pacemakers to prevent bradycardia since the invention of the portable/wearable pacemaker in the 1950s and the widespread use of the implantable device in the 1960s [6]. In addition, the most modern leadless pacemakers [15] use only the ventricular pacing. Many implantable cardioverter defibrillators (ICDs) use only the ventricular pacing to restore unstable or failed heart rate to its normal beating through timed electrical shock delivery.
