ECG Tutorial. Volume 1 (review)

ECG Tutorial. Volume 1. By Leonard S. Gettes. Armonk, NY: Futura, 2000. CD-ROM, $125.

Electrocardiography remains the most commonly used diagnostic test in cardiology. It is the key to the diagnosis of cardiac arrhythmias and, often, to the diagnosis of acute coronary syndromes and other important disease processes. For a fellow in cardiology training, the recommended minimal number of ECGs to read is 3,500, but too often fellows read without much understanding of the underlying anatomical, pathophysiologic, and electrophysiologic processes. Because most medical schools provide only a brief introduction to electrocardiography, the knowledge of most physicians other than cardiologists (or internists who have had a special interest in cardiology) is limited.

I have taught electrocardiography for more than 30 years and frequently have been asked to recommend books and teaching materials, particularly for self-study. Until now, I have had trouble making a strong recommendation. I have always based my teaching on anatomy, cellular electrophysiology, and both solid angle and vectorial analysis of activation and repolarization. In 1978, I prepared a four-part slide-tape for the American Physiological Society (APS) based on these concepts. In recent years, as I have become increasingly involved in the development and use of interactive CDs and the internet for teaching, I had hoped to prepare a multimedia computer-based product on electrocardiography utilizing the concepts in the APS slide-tapes, since I believe such electronic instruction is the wave of the future. But this was one of those projects for which I never seemed to have the time.

I am very pleased that Dr. Leonard Gettes found the time and, along with programmers David Beane and David Martin, as well as graphic artist Derek Parr, developed such a CD-based program. Gettes, the Henry A. Foscue Distinguished Professor of Cardiology at the University of North Carolina at Chapel Hill, is an internationally known researcher and cardiologist whose electrophysiologic research has ranged from the cell to the patient. He is one of the few ideally suited to developing this ECG tutorial.

Dynamic concepts—such as the flow of ions through membrane channels and between cells, action potentials, vectorial concepts, changing charge distribution, the movement of dipoles, and normal and abnormal sequences of electrical activation—are ideally demonstrated by computer animation, which is far superior to the static images in books or in my slide-tapes. Gettes succeeds in clearly explaining through the graphics and text concepts that most students, fellows, and more senior physicians find challenging, if not incomprehensible; the reward for mastering those concepts is that the user develops an intellectual framework that makes "pattern-reading" of electrocardiograms understandable. The clinical examples are well-chosen, and making it possible to magnify portions of the electrocardiogram to focus on details was inspired.

The CD is well-organized, easy to navigate, and includes the following sections: generation of the ECG; the normal ECG; intraventricular conduction disturbances; ventricular hypertrophy; electrolyte abnormalities, drug effects, and long QT syndrome; ischemia and infarction; tachycardias; and bradycardias. Another section is devoted to a correlation of the cardiac examination, particularly heart murmurs, with the ECG. The final section considers the use of the ECG in the emergency department.

I have a few criticisms. If medical students are an important market, the price is high. It would also be useful if the ECGs could be printed out, either to be distributed by a teacher prior to analysis using the program or to be analyzed by the student on a table top using a full-sized ECG and calipers. Some of the sections would have benefited from audio explanations as well as the written descriptions of events on the graphics. The color scheme could be improved: white text on a black background is harder to read than the reverse or some other color combinations, particularly if one relies on laptop computers with small screens, as many students do. Some topics should have been illustrated with animation, such as the relationship between the...