Infant ventricular fibrillation after ST-segment changes and QRS widening: a new cause of sudden infant death?

BACKGROUND Ventricular arrhythmia-related sudden cardiac arrest in infants with structurally normal hearts is rare. There have been no previously published reports of infants <3 months of age with ventricular fibrillation in which a primary diagnosis could not be defined. METHODS AND RESULTS Retrospective chart review of 3 unrelated infants <2 months of age from 3 different tertiary care centers within the United States and Australia was conducted. All 3 infants survived sudden cardiac arrest secondary to multiple episodes of polymorphic ventricular tachycardia and ventricular fibrillation. Each infant demonstrated unique and transient ECG findings consisting of ST changes and QRS widening before arrhythmia onset, which have not been previously reported. Amiodarone, sedation, sodium channel-blocking agents, and ventricular pacing were effective in suppressing acute events. Despite thorough investigation, including genetic testing, the cause of ventricular arrhythmias in each of these infants remains unclear. CONCLUSIONS This is the first report of idiopathic ventricular fibrillation in young infants preceded by stereotypical transient ECG changes. These findings may represent a new, potentially treatable cause of sudden infant death. Recognition of these prodromal changes may be important in future management and survival of these infants.