抄録
The author calculated the vector of the electric charge of a heart by P-wave in the standard EKG that investigated by 321 healthy men, by means of Maekawa's orthogonal isosceles triangle coordinates. Mostly they turn to the left quadrant of this coordinates from the right that they are started, and stop in the left quadrant. It is easy to understand, when we image the time related with stimulation of both auricles which is caused by the position of the sinus-knot, through the theory of chain-doublets and the existence of the intraauricuiar specific muscular system, that first of all the right auricule is stimulated, and when P-wave is beginning its action, the direction of the electric charga of a heart marks at the right quadrant, and then the direction is turned by stimulation of the left auricle, and it marks at the left quadrant, when P-wave situates in the last time.
