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A Renaissance in Electrocardiography

Electrocardiography began more than a century ago when Waller and Einthoven introduced the electrocardiogram (EKG(Dutch); ECG (English)) for registering the electrical activity of the heart from the surface of the body. The evolution of electrocardiography can be categorized into three phases:1 the Introductory Phase (1890–1940) began with the invention and progressed as technical improvements were added and numerous descriptive reports relating ECG findings to specific cardiac disorders were published;2 the Diagnostic Phase (1940–1990) started with the introduction of the full 12-lead ECG (1942) and grew as the 12-lead ECG and dynamic exercise and Holter recordings became widely used and accepted in the everyday practice of clinical medicine and cardiology; and3 the Renaissance Phase (since 1990) reflects a new appreciation of the ECG as an invaluable tool for providing fundamental insight into the basic electrophysiology of the heart in health and disease in the current era of molecular genetics and electrical device therapy. The Renaissance Phase draws heavily on the earlier clinical accomplishments and technical improvements during the 50-year Diagnostic Phase beginning in the 1940s. Although the ECG became a widely accepted diagnostic tool, new invasive diagnostic techniques such as programmed electrophysiologic testing were introduced in the 1980s. This “new kid on the block” held great promise for identifying patients at risk for sudden cardiac death. Classical electrocardiography was thought to have achieved almost its entire potential, and the general feeling was that it was time to move on to new and more sophisticated diagnostic electrical techniques. Furthermore, the introduction of new electrical therapy with pacemakers and exter-