The development of the electrocardiograph was the culmination of a scientific effort aimed at perfection of a device conceived for the elucidation of a physiologic phenomenon. The development of the digital computer was the culmination of a scientific effort aimed at perfection of warfare. Both of these fairly recent innovations of modern technology have been moderately successful in their initial objectives. Electrocardiography has had a profound influence on the practice of medicine. On the global scene, computers have so far had an insignificant influence on the practice of electrocardiography. In North America, however, computer interpretation of ECGs has already made a modest impact, perhaps more in terms of commercial gains rather than producing a substantial benefits to health care. The introduction of computers into clinical electrocardiography has not resulted in any widespread application of improved diagnostic criteria. The automation of ECG interpretation has not resulted in reduction of the cost of health care, on the contrary, in general it has increased the cost. Perhaps the most dismal failure has been the negligible use of computers in epidemiologic studies and heart disease prevention efforts. Palmistry, astrology, the art of palpation of the pulse, auscultation and acupuncture have had a more profound influence on the practice of medicine than computer analysis of the electrocardiogram. On the positive side, one of the beneficial effects of the use of computers has been the increasing awareness of the limited diagnostic accuracy of currently used ECG criteria, and the recognition of the fact that a substantial improvement is warranted; if such improvement can not be achieved in the foreseeable future, electrocardiography will lose much of its current clinical utility. Computers have had a profound influence on research in electrocardiology, and although a very few tangible concrete results have thus far diffused into clinical electrocardiography, their impact can be expected during the last two decades of this century. Computers will produce at least containment of costs if not actual net cost reduction in clinical electrocardiography. Computer analysis will rapidly antiquate the present primitive visual ECG classification in epidemiologic studies and clinical heart disease intervention trials. Computer analysis will enhance the diagnostic accuracy of the electrocardiogram. However, a radical departure from the current ECG display and interpretation practice will be mandatory before any substantial breakthrough can be materialized. All these anticipated evolutionary and perhaps even revolutionary changes will require a continuing intensive research effort, a change in the professional attitude of practicing electrocardiographers and a considerable effort in professional education. Finally, the elucidation and exploration of the full diagnostic and predictive value of the ECG remains the challenge of first magnitude in electrocardiography...