Programmed electrical stimulation, the signal-averaged electrocardiogram, and the implantable cardioverter-defibrillator in ventricular arrhythmias.

In the last year the technique of programmed electrical stimulation has been further developed and more fully evaluated when used for the assessment of an individual's risk from ventricular arrhythmias. The method of recording and analyzing signal-averaged electrocardiograms has recently undergone considerable technical development, especially in the frequency and spectrotemporal domains. The importance of late potentials as a risk factor for arrhythmic events in the convalescent period following acute myocardial infarction is less clear in patients who have received thrombolytic therapy. The implantable cardioverter-defibrillator is now fitted to over 10,000 new patients each year, yet its true value has not yet been prospectively assessed. However, it is known that fitting the device is associated with a considerable operative mortality, and the device does not completely eradicate sudden death. Furthermore, the cost of this form of therapy is very high and its prophylactic use has not been established.