What is it 

A pacemaker is a battery-powered device placed under the skin or the muscle (usually on the anterior chest) connected to different heart chambers with leads (cables). An electrical impulse sent through the leads will cause the heart to beat whenever is needed. Single chamber pacemakers have one lead, dual chamber pacemakers have two, and biventricular pacemakers have three leads (Fig 1). In addition, the Micra® and Nanostim® single chamber pacemaker have only recently become available and are made of a capsule slightly bigger than the size of the coin (Fig. 2). The capsule contains the whole pacemaker “head” and battery, is implanted from the femoral vein (a large vein in the groin) into the right ventricle (the chamber that pumps blood into the lung), and does not require surgical incision of the chest or placement of any leads in the heart (Fig. 2). Patients are usually discharged 2 days after the operation.