Assessment and follow-up of pediatric survivors of sudden cardiac death

In the young patient resuscitated from sudden cardiac arrest, the risks of recurrence are uncertain and so are the criteria defining therapeutic efficacy for the presumed cause of the initial event. In this study, we analyzed the outcome of 15 consecutive young patients, who were resuscitated from pulseless ventricular tachycardia or ventricular fibrillation and who were evaluated by comprehensive hemodynamic and electrophysiological testing. Patients were 11.2±2.7 (mean±SD) years old at the time of their event, and each was known to have some form of heart disease before sudden cardiac arrest. Ventricular tachycardia or fibrillation was inducible by programmed electrical stimulation in eight patients. Accessory atrioventricular connections, with antegrade effective refractory periods less than 220 msec, were identified in three patients. Sustained atrial flutter was the only arrhythmia inducible in two patients, and no arrhythmias were inducible in two other patients. Surgical or electrophysiological-guided medical therapy resulted in noninducibility of the ventricular arrhythmias in six patients. Surgical division of the accessory atrioventricular connections was performed in three patients, and arrhythmias were not inducible after operation. The four patients with atrial flutter or without defined arrhythmia were treated with an empiric therapy. During 37±14 months of follow-up, the nine patients with documented noninducibility of a defined cause of sudden cardiac arrest were free of recurrent events. In contrast, during 18±10 months of follow-up, two of the six patients with empiric therapy or persistent inducibility of ventricular tachycardia died suddenly, and three others had recurrence of ventricular tachycardia or fibrillation. Suppression of inducibility of a tachyarrhythmia consistent with sudden cardiac arrest was the only variable correlated with improved outcome (p=0.03). Young survivors of sudden cardiac arrest are at high risk for recurrent life-threatening events, unless the efficacy of their therapy is proven by electrophysiological testing. Cardioverter-defibrillator therapy may improve the otherwise guarded prognosis of patients without proven therapy.