Abstract
The author has found that the right hand electrode detects extracellular potential in endocardium and the left foot electrode detects the extracellular potential of epicardium, and if the epicardial potential subtracted from the endocardial potential, the results will be set to surface electrocardiogram. In a normal electrocardiogram, the resting potential of endocardium and epicardium are the same voltage and depolarizing potential are also the same. Hence there is no difference between base line and ST segment. However there are four combinations in abnormal situations, namely higher or lower voltage of epicardium in resting state or in depolarizing state. This article is written about the four corresponding diseases : angina pectoris, myocardial infarction, Brugada syndrome, and early repolarization syndrome.
