The Intrinsic Component Theory of Electrocardiography

Abstract
A new theory, the intrinsic component theory, is proposed for electrocardiography. This theory is based on the temporal characteristics rather than spatial orientations of the current sources and sinks in the heart. The theory may be stated as follows: the electrical activities of the heart may be decomposed into spatially nonorthogonal, stationary sets of current sources and sinks. The time variations of the magnitudes of all the sources and sinks belonging to the same set follow a single pattern of an intrinsic component which is orthogonal (uncorrelated) in the time domain to all other intrinsic components. The physical interpretation of intrinsic components is new to electrocardiography, although the mathematical tool employed is the well-known eigenvalue process. The intrinsic component theory, applied to a single dipole, provides us with a mathematical foundation for vectorcardiogram rotation, and a better basis for pathological ECG comparison and classification, especially by digital computers.