(1) The main purpose of this communication is to introduce a newly devised experimental technique for studying electrocardiography and vectorcardiography: a canine heart perfused by means of Langendorff's technique was placed within a transparent plastic molded human torso model filled with Tyrode solution at the physiological temperature of 36°C, the heart was kept beating regularly by the sinus rhythm for more than 2 hours, and it was succeeded in obtaining recordings of the electrical activity of the heart by Frank lead system and by the conventional electrocardiographic leads.
(2) This method contains advantages inherent in both the simplified physical model experiment and the in situ experiment without including disadvantages ascribed to each of the 2 experimental approaches. It can be expected that this method be adopted in many aspects of electrophysiological investigation of the heart.
(3) As an application of this technique, relationship between rotation angle of the suspended canine heart and changes in QRS pattern of electrocardiogram and vectorcardiogram were investigated.