A Review of Cardiac Pacemakers

Pacemakers are electronic devices that stimulate the heart with electrical impulses to maintain or restore a normal heartbeat. Today we tend to think of implantable cardiac defibrillators (ICDs) as an extension of a pacemaker, one with a capacitor that allows the delivery of a defibrillator charge. It seems only natural that once a pacemaker was built, an ICD would also be built. However, the development path for early ICDs was mostly separate from pacemakers and was, unlike pacemakers, developed by a single group. In fact, even as pacemaker use was growing, the very idea that and ICD could work was greeted with skepticism by many experts. Cardiac pacemakers are one of the most frequently encountered cardiac devices seen on chest imaging. They may include single or dual chamber pacemakers, automated implantable cardioverter defibrillators (AICD), biventricular pacemakers used for cardiac resynchronisation therapy (CRT), wireless CRT, leadless pacemakers, and subcutaneous implantable cardioverter defibrillators (SICD). This review aims to provide an up-to-date review on cur rent implantable pacemaker and defibrillator devices.