Role of programmed stimulation in assessing vulnerability to ventricular arrhythmias.

Programmed electrical stimulation can now be safely performed in humans for the evaluation of therapy for recurrent ventricular tachyarrhythmia. Such studies may also eventually be found useful in predicting the risk of developing life-threatening ventricular tachyarrhythmias. The repetitive ventricular response phenomenon has been evaluated. Although an association between the intraventricular reentrant phenomenon and sustained ventricular tachyarrhythmias has been found, its predictive value in a population at risk is not sufficient for use in clinical decision making. On the other hand, the initiation of sustained ventricular tachycardia or fibrillation appears closely related to its actual spontaneous clinical occurrence. Serial electrophysiologic studies can be performed and are effective in prospectively evaluating the response to antiarrhythmic drugs. The efficacy of therapy based on the results of programmed stimulation appears to be good.