Abstract
We are now in the possession of a method and sufficient anatomic and physiologic information for a detailed and fairly accurate analysis of the normal and pathologic spread of the excitation wave in the human heart. Such an analysis will help to clarify some of our somewhat hazy and even inaccurate ideas asto the causes of the form of the normal and pathologic electrocardiogram. Using the method of the equilateral triangle devised by Einthoven,1 I attempted an analysis of the propagation of the wave of electronegativity in the human heart in 1914.2 This paper has for its purpose the more extended introduction of the method among American clinicians and a revision of some of the ideas developed in that paper. The work of Rothschild and Lewis3 on the velocity of conduction in the heart muscle has been especially helpful in revising our ideas as to the propagation of the electronegative