The following is an exerpt from Tex Heart Inst J. 2002; 29 (3): 164–171

During the latter part of 19th century, much research centered around the electrical activity of the heart, although some of the 1st investigators were unaware of the clinical usefulness of recording cardiac electrical activity. As late as 1911, Augustus Waller, who was the pioneer of electrocardiography, said, “I do not imagine that electrocardiography is likely to find any very extensive use in the hospital. It can at most be of rare and occasional use to afford a record of some rare anomaly of cardiac action.” However, just 13 years later, the Nobel Prize in Medicine was awarded to Willem Einthoven, who transformed this curious physiologic phenomenon into an indispensable clinical recording device.

Rudolf von Koelliker and Heinrich Müller were the first to discover, in 1856, that the heart generated electricity. The 1st successful recording of electrical rhythm in the human heart seems to have been made by Alexander Muirhead in 1869–70, using a Thomson siphon recorder at St. Bartholomew's Hospital, London. This equipment was originally devised to record signals passing through the transatlantic cable, which had been laid in 1866. Waller performed his work in the development of electrocardiography at St. Mary's Hospital, Paddington, London. He used the Lipmann capillary electrometer to record electrical reactions of the human heart. In 1887, Waller published the 1st report of a recording of cardiac electricity on the body's surface; he called the recording a “cardiograph.” Waller presented his paper titled “A preliminary survey of 2,000 electrocardiograms” before the Physiological Society of London in 1917. Among his contributions were the variability of the electrogram, the dipole concept that led to isopotential mapping, and the vector concept.

Einthoven, born in 1860 in Java, Dutch East Indies (now Indonesia), attended the University of Ütrecht Medical School. In 1887, Einthoven was present at the International Congress of Physiology in London, where he observed Waller demonstrating the use of the capillary electrometer to record an “electrograph” of the heart. Einthoven began to explore the use of the capillary electrometer to record minute electrical currents. In 1895, he was able to detect recognizable waves, which he labeled “P, Q, R, S, and T.” The limitations of capillary electrometers led Einthoven to devise a string galvanometer to record cardiac electrical activity.With his new technique, he standardized the tracings and formulated the concept of “Einthoven's triangle” by mathematically relating the 3 leads (Lead III = Lead II – Lead I). He described bigeminy, complete heart block, “P mitrale,” right and left and ventricular hypertrophy, atrial fibrillation and flutter, the U wave, and examples of various heart diseases. Johannes Bosscha, one of Einthoven's teachers, suggested using existing telephone lines to link the hospital to Einthoven's physiology laboratory. This idea increased the clinical availability of Einthoven's instrument by enabling electrocardiographic studies to be made in hospitalized patients.

Within 10 years of Einthoven's clinical studies with the string galvanometer, the potential of electrocardiography was realized. Many arrhythmias were recognized, and the associations of T-wave inversion with angina and arteriosclerosis were identified in 1910. The “father of electrocardiography” was honored with the Nobel Prize in Medicine in 1924. His important contributions laid the foundation for the great discoveries of the 20th century and further advances in the field of cardiology.