Fibrillar Contraction of the Heart

MANY years ago Ludwig and Hoffa' showed that the application of strong constant currents or faradic currents to the ventricles of the dog's heart causes an abolition of the normal beat. The ventricular muscle is thrown into a state of irregular arhythmic contraction, whilst there is a great fall in the arterial blood pressure. Thie ventricles become dilated with blood as the rapid quivering movement of their walls is insufficient to expel their contents; the muscular action partakes of the nature of a rapid incoordinated twitching of the muscular tissue. This condition persists for a very long time in the dog, and as Ludwig showed, it is possible to kill an animal in this way-by applying a faradic current to the ventricles. The auricles go on beating rhythmically; they do not participate in the irregular movement excited in the ventricles. These phenomena are familiar to all who have wvorked much with the mammalian heart; they have been designated by various names-Herz-delirium, Delirium cordis, Fibrillar contraction, Intervermiform movement, &c. During the last two years I have performed a large number of experiments bearing uporn this subject. My earlier investigations were pursued in the Physiological Laboratory of University College, London, and the more recent ones in the Physiological Laboratory of the University of Aberdeen. I have studied the phenomena in question in the hearts of the dog, cat, rabbit, rat, mouse, hedgehog and fowl; both in the young animal and in the adult. The experiments were all conducted on completely anaesthetised animals; artificial respiration was carried on, a cannula being inserted in the trachea; the thorax was opened in many cases and the heart laid bare; the temperature of the animal was kept up by means of a warm pan.