ABSTRACT
Rapid advances in pacemaker technology have led to a remarkable increase in pacemaker sophistication, such that a wide range of different functions is now available. The most basic function of a pacemaker is to provide a ‘safety net’ for patients at risk of bradycardia. Implantable cardioverter defibrillators (ICD) have proved to be invaluable in the management of life-threatening ventricular arrhythmias. Only a little larger than permanent pacemakers, they are implanted subcutaneously, usually in the same location as permanent pacemakers, although some of the older, bigger, units were implanted abdominally. ICDs continually monitor the cardiac rhythm looking for ventricular arrhythmias. The parameters by which ICDs diagnose arrhythmias and respond to them can be individually programmed into the device after it has been implanted, so that treatments most appropriate to the patient’s condition can be chosen. ICDs are expensive but effective, and many trials have shown marked reduction in mortality.
