Joseph C. Solomon

The ECG: QRS Change

Known and measured cardiac and torso anatomy, electrophysiology, and resistivities have been incorporated into a three-dimensional propagation model of ventricular excitation [1]. This model includes all the first-order effects known to influence the ECG in man. It has been used to generate QRS criteria for the 12-lead ECG in order to locate infarcts in 12 segments of the left ventricle and to predict the amount of infarct in each segment [2, 3]. The ability of these criteria to predict the size of infarct in each of the three main coronary artery distributions is the subject of this chapter.

Current dipole moment density of the heart

Abstract A model of the current dipole moment associated with the region of the myocardium undergoing ventricular depolarization is postulated. The model was investigated in a series of dog experiments employing the technique of intramyocardial differential electrodes to measure the maximum electric field and distance between sources and sinks of current. Analysis yields a value of 26 mv. for the electromotive force of the activating front with a current dipole moment density of 1.8 × 10 −13 coul-m per square meter. For the purpose of simulating electrocardiographic data in humans with a mathematical-physical model, the following first order approximation is given: the current dipole moment density associated with normal ventricular muscle undergoing depolarization is uniform throughout the myocardium with a value of 1.8 × 10 −13 coul-m per square meter.