Outcome of Ventricular Fibrillation in Children

Abstract

Source: Samson RA, Nadkarni VM, Meaney PA, et al. Outcomes of in-hospital ventricular fibrillation in children. N Engl J Med. 2006;354:2328–2339; doi:10.1056/NEJMoa052917Ventricular tachycardia and fibrillation are among the most common causes of cardiac arrest in adults and “shockable” rhythms have been associated with improved survival. However, children more typically suffer electrocardiographic asystole or pulseless electrical activity as the consequence of hypoxia from other organ system disease progression rather than a primary cardiac arrest.The authors evaluated patients (<18 years of age) with inhospital cardiac arrests captured in the National Registry of CPR, a large, multi-center database sponsored by the American Heart Association. They investigated whether children with initial ventricular tachycardia or fibrillation as the cause of cardiac arrest had improved survival when compared to children who developed ventricular dysrhythmias prior to the start of cardiopulmonary resuscitation (CPR). The study period was January 2000–June 2004 and included 1005 children who experienced a cardiac arrest.One hundred-fifty cases (15%) were excluded because the initial cardiac rhythm was unknown. Of the 855 cases reviewed, 104 children (10%) had initial ventricular tachycardia or fibrillation, and 35% survived to hospital discharge. Thirty-four of 36 survivors had a good neurologic outcome. Of the 149 children (15%) who developed ventricular tachycardia or fibrillation during resuscitation, only 11% survived to hospital discharge and 12 of 16 survivors had a good neurological outcome. Among children who never had documented ventricular tachycardia or fibrillation (n=733, 73%), 27% survived to hospital discharge and 144 of 164 survivors had a good neurological outcome.The authors conclude that children with initial ventricular tachycardia or fibrillation had improved survival compared to children who never had ventricular tachycardia or fibrillation and compared to children who developed ventricular dysrhythmias during CPR.Dr. Bratton has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of a commercial product/device. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.This report and another recent study1 using the same database reports improving survival of children after CPR. In-hospital arrest survival in this cohort was 27% for children overall which is much better than prior reports.2 Furthermore, 65% of those who survive do so with acceptable neurological outcomes.1The current paper shows that approximately 10% of children had initial ventricular tachycardia or fibrillation, and that their survival is better than children with other initial pulseless rhythms. However, the prognosis for pediatric patients who develop ventricular fibrillation or tachycardia during CPR is worse. This finding conflicts with experimental reports demonstrating improved outcome with induction of ventricular fibrillation during CPR for asystole, followed by defibrillation.3 The authors speculate on the reasons for this finding and question whether excessive administration of epinephrine or underlying myocardial status play a role; however, they conclude that their data cannot answer that question.Pediatricians need to review the new CPR guidelines published by the American Heart Association,5 which have changed to focus more immediately on maintaining and optimizing circulation. Further training is needed to recognize and treat “shockable” rhythms. Patients with initial ventricular tachycardia or fibrillation have a better prognosis than children with asystole or pulseless electrical activity, but this must be recognized quickly in order to give appropriate treatment. New potential advances to further improve survival after pediatric CPR may include use of hypothermia or ECMO but these therapies require further study.We wonder whether monitoring of the children who developed ventricular fibrillation during resuscitation may have been less likely prior to their arrest than those whose arrest was due to a ventricular arrythmia, resulting in a delay in initiating the advanced life support measures that might have improved outcomes in this subset of patients.