About the "electric position" of the heart

From the point of view of adherents of the concept of "locality" of unipolar leads, biopotentials related only to those areas of the heart muscle that are "adjacent" to the differential electrode, namely, to the epicardial surface of the left ventricle, are recorded in the thoracic leads of 5-6. In this regard, the ECG in U5—6 is usually compared in form only with those leads from the extremities, which, firstly, are also unipolar and to which, secondly, the epicardial surface of the left ventricle can adjoin. Adherents of the considered "localistic" concept believe that aVL can satisfy these conditions if the electrical position of the heart is horizontal, or aVF if it is vertical (Wilson et al., 1944). Similarly, the similarity with aVL or aVF of the ECG in the thoracic leads of U1—2 is evaluated, which, according to the mentioned view, reflects the bioelectric activity of the right ventricle, namely its epicardial surface.