The Significance of Abnormalities in the Form of the Electrocardiogram

Much interest has recently been shown in the relation of changes in the form of the electrocardiogram to disturbances of the myocardium. This interest is centered for the most part about changes in the form of the ventricular portion of the electrocardiogram, which have been interpreted as indicative of faulty conduction of the cardiac impulse through the ventricles. The abnormal form of the electrocardiogram, to which attention is directed in this paper, consists in a prolongation of the initial group of waves of the ventricular portion, the so-called Q-R-S group, with notching or splitting of the main wave, the R wave. A consideration of this portion of the electrocardiogram is important, as it renders valuable information concerning the state of the myocardium, and has proved of distinct value in determining the diagnosis and prognosis in numerous cases of heart disease. It is a well established fact that the electrical phenomenon