Paroxysmal tachycardia of ventricular origin is one of the rarest disturbances of the cardiac mechanism. The first case with electrocardiographic tracings was recorded by Lewis1in 1909. Robinson and Herrmann2recently reported four cases and discussed the criteria on which they consider a diagnosis justifiable. The points emphasized by these authors may be stated briefly as follows: Electrocardiograms are necessary to differentiate ventricular tachycardias from those of auricular origin. The condition is most clearly shown when a succession of auricular complexes can be made out occurring independently of and at a slower rate than the complexes of ventricular origin. The ventricular complexes are distinctly abnormal in form; but this alone cannot be taken as absolute proof that the impulses are of ventricular origin, as changes in form may be caused by disturbances in intraventricular conduction. The presence of isolated ectopic ventricular beats before or after a paroxysm is is regarded as evidence in