Cardiac pacemakers are divided into three types according to the location of the electrode lead implantation: 1) single-chamber pacemakers, where the electrode lead is placed in the right ventricular apex or in the right ear; 2) dual-chamber pacemakers, where two electrode leads are implanted in the right ear, atrium and right ventricular apex, and ventricle for atrial sequential pacing; 3) triple-chamber pacemakers, mainly divided into dual atrial plus right ventricular triple-chamber pacemakers and right atrial plus dual ventricular triple-chamber pacemakers. Pacemakers. The cost of pacemakers varies according to performance and age.