On Mathematical Reconstruction of T Wave Patterns ; Representation of Equivalent Cardiac Generator during Repolarization and Interpretation of Concordance of T Wave with QRS Complex

The theoretical explanation of the genesis of electrocardiographic T wave is subjected to one of the most perplexing points of debate. Various hypotheses to give its explanation have been proposed by different investigators, however, their explanations would seem to be rather inadequate as compared with that of the genesis of QRS complex. For the electrical activity of the heart during depolarization, its electrical source can be equivalently represented by the electrical double layer at the border of activation wave front. Furtheremore, the activation process during depolarization can be determined by means of the intrinsic deflection on the relevant electrocardiogram, when the tracing of a unipolar or contiguous bipolar lead is obtained from the surface of the heart or from the intramural cardiac mass. On the other hand, at the time of repolarization, there is no discernible intrinsic deflection to be registered by the extracellular lead, therefore, the repolarization process can not be easily investigated by any electrogram recorded extracellularly. At the present time, the re-polarization process can be observed only at the limited portion of the heart, that is, at the individual cardiac muscle fiber of the subepicardial layer by means of the intracellular microelectrode technique. In this study, using the tracing of repolarization phase of transmembrane action potential, the electromotive force during repolarization was discussed, and the construction of normal T wave was carried out, by using the speculated difference in pattern of the transmembrane action potential of cardiac fiber in the various layers of the heart muscle. Theory and Computation : It is considered that the electrocardiogram is the total sum or the superposition of the action current generated by individual excited cardiac muscle fiber, which is a spatial and time-varying function. The transmembrane action potential of its fiber can be registered by means of microelectrode method, although its action current can not.