Prognostic significance of arrhythmia inducibility or noninducibility at initial electrophysiologic study in survivors of cardiac arrest.

The value of arrhythmia inducibility or noninducibility at initial electrophysiologic study to predict the likelihood of arrhythmia recurrence was assessed in 150 consecutive survivors of cardiac arrest. Ventricular tachycardia (greater than or equal to 6 beats) or ventricular fibrilation was induced in 113 patients (75%); ventricular arrhythmia could not be induced in 37 patients (25%). During follow-up of a mean of 16 months (range 1 to 72), there were 65 arrhythmia recurrences, 34 of them fatal, in 58 patients. Multivariate regression analysis showed that inducibility at initial study of ventricular tachycardia or ventricular fibrilation was an independent predictor of total arrhythmia recurrence (p less than 0.0001) and fatal arrhythmia recurrence (p = 0.02). At 1 year, 25 +/- 5% of patients with an inducible arrhythmia had a fatal arrhythmia recurrence compared with only 4 +/- 4% of patients without (p = 0.003). The nature of the inducible arrhythmia had no additional predictive value. Inducibility or noninducibility of ventricular arrhythmias at initial electrophysiologic study is a powerful, independent predictor of subsequent arrhythmia recurrence in survivors of cardiac arrest. Patients without inducible arrhythmias have a low frequency of fatal arrhythmia recurrence.