<P> CRT devices have been shown to reduce mortality and improve quality of life in patients with heart failure symptoms; a LV ejection fraction less than or equal to 35% and QRS duration on EKG of 120 ms or greater . </P> <P> Biventricular pacing alone is referred to as CRT - P (for pacing). For selected patients at risk of arrhythmias, CRT can be combined with an implantable cardioverter - defibrillator (ICD): such devices, known as CRT - D (for defibrillation), also provide effective protection against life - threatening arrhythmias . </P> <P> A major step forward in pacemaker function has been to attempt to mimic nature by utilizing various inputs to produce a rate - responsive pacemaker using parameters such as the QT interval, pO--pCO (dissolved oxygen or carbon dioxide levels) in the arterial - venous system, physical activity as determined by an accelerometer, body temperature, ATP levels, adrenaline, etc . Instead of producing a static, predetermined heart rate, or intermittent control, such a pacemaker, a' Dynamic Pacemaker', could compensate for both actual respiratory loading and potentially anticipated respiratory loading . The first dynamic pacemaker was invented by Anthony Rickards of the National Heart Hospital, London, UK, in 1982 . </P> <P> Dynamic pacemaking technology could also be applied to future artificial hearts . Advances in transitional tissue welding would support this and other artificial organ / joint / tissue replacement efforts . Stem cells may be of interest in transitional tissue welding . </P>

When was the pacemaker invented in what year