Part V deals with the application of bioelectromagnetism to cardiology. This subject is discussed in more detail than the application of bioelectromagnetism to neurophysiology because the historical development of the theory of bioelectromagnetism is strongly associated with developments in electrocardiology.
The 12-lead system, discussed in Chapter 15, was an early clinical application of bioelectromagnetism. Theoretically, it is very primitive. Vectorcardiographic lead systems, discussed in Chapter 16, are based upon more advanced theory of volume conductors than the 12-lead system. Chapter 17 includes a further theoretical development of more complicated lead systems which, however, are not in clinical use. Chapter 18 explains briefly the various distortion effects of the real thorax.
The short introduction to clinical ECG diagnosis in Chapter 19 is included in this book, not to serve as an introduction to clinical studies but to give the reader an impression of what kind of changes in the clinical ECG signal are found owing to various pathological conditions in the heart. This permits, for instance, the clinical engineer to understand the basis of the technical requirements for an ECG amplifier and recorder.
Like Part IV, Part V also includes (in Chapter 20) a discussion of the detection of the magnetic field due to the electric activity of the heart muscle.