Ventricular fibrillation in the neonate: elusive or illusive?

Ventricular fibrillation (VF) in mature large mammals is usually a terminal event. It constitutes the most common mode of exitus and the main cause of sudden cardiac death in humans. In neonates, VF is of particular interest because it often reverse spontaneously and promptly to potentially become a non-lethal event. Accordingly, the study of VF and spontaneous defibrillation (SDF) in the neonate is key for the understanding of the developmental anatomical and functional characteristics enabling mammalian myocardium to initiate and sustain this lethal arrhythmia. Such characteristics may include age-related changes of myocardial tissue properties, mass and geometry, autonomic cardiac innervation and myocardial perfusion/hydration. In the human neonate, VF/SDF could provide a plausible framework for explaining and directing the search for the elusive evidence underlying the mechanism and age distribution of the sudden infant death syndrome.