Analog Computer Model of the Vectorcardiogram.

THE formation of a model is an important phase of all scientific thinking in that it serves to demonstrate or explain the workings of an inherently complex natural system in terms that can be more readily understood. In electrocardiography, the Einthoven tri-angle' has been used for years as a relatively simple geometric model of an essentially complex volume conductor, the human torso. This model, in spite of many oversimplifications , has served for over 50 years as a useful reference frame for a vast amount of data and theory. More recently, the definitive mapping study by Scher2 of the sequence of myocardial depolarization in dogs, again a simple model of a very complex phenomenon, has served to illuminate and clarify a vast body of empirical data. This model has added greatly to our understanding of previously confusing findings in electrocardiography and vectorcardiography.