The Influence of the Inhomogeneities of Electrical Conductivity Within the Torso on the Electrocardiogram as Evaluated from the View Point of the Transfer Impedance Vector

Abstract

As one of the tissues possessing profound influence on body surface ECG, the lung was especially studied through placing dog lungs or a lung model in the human torso model. As the electrical source, an artificial current dipole or dog heart perfused according to Langendorf's technique was used to study the influence of the lungs on the transfer impedance vector and body surface ECG. The image surface of the inhomogeneous model (with the lung model) showed shrinkage on the dorsal side with interpolation of the lung as compared with the homogeneous model. In the portion without interpolation of the lung, it enlarged under the influence of the lung. On the homogeneous model, the orthogonal systems of Frank and Polyograph III demonstrated very good performance in normality and orthogonality. But the emplacement of lungs caused considerable deterioration of these VCG systems. A very good correlation was noted between the changes of body surface ECG and those of the transfer impedance vector in the homogeneous and inhomogeneous model. The lead field-potential distributions within the human torso were measured. From this result, it was concluded that an electric current tended to flow towards the regions where the lungs did not intervene. © 1970, International Heart Journal Association. All rights reserved.