The interest in ventricular fibrillation as a disturbance of the cardiac activity of man has been centered about the rôle this phenomenon may play in causing sudden death. It has been generally accepted that when the human ventricles pass into a state of fibrillation, death is an almost immediate and invariable consequence.
Ventricular fibrillation can be determined definitely by electrocardiograms, as its presence is indicated by a well defined type of record. This type has been frequently obtained from animals in which ventricular fibrillation was directly observed in the exposed heart. The usual waves that are produced by the passage of the excitation impulse through the ventricles and the resulting contraction disappear and in their place rapidly recurring, more or less irregular, waves occur following each other so closely that no period of cardiac inactivity is indicated. The waves vary in height and in form, and short stretches during which