Naming of the Waves in the ECG, With a Brief Account of Their Genesis

The purpose of this presentation is 2-fold: to tell the stories of the naming of the waves in the ECG and to discuss briefly the electrical activity that produces them. ### Naming the PQRST and U Waves In March 1997, I wrote to Howard Burchell to inquire if the legend about the naming of the waves in the ECG was true or not. Did Einthoven really have the foresight to recognize that by choosing letters near the middle of the alphabet, letters would be available to label waves that might be discovered later? Burchell’s response, dated March 31, 1997, is reproduced below: I could never get a direct confirmation that the letters were intentionally chosen from the middle of the alphabet, but Snellen, his “official biographer,” has said so, and he should know. There is another hypothesis put forward by Henson—relating an explanation of “P” standing for a point in a Descartes scheme—in the Journal of the History of Medicine and Allied Sciences 1971, 26:181. A note on Descartes seems appropriate because although he was born in France in 1596 and died in 1650, he plays a major role in the story that unfolds.1 He invented analytical geometry. He was the first scientist to state the law of refraction, and he labeled some of the points on the curves he drew P and Q. As discussed later, Einthoven undoubtedly studied the work of Descartes, as did all serious students of geometry and physics. The first human ECG, recorded by Waller2 in 1887 with Lippmann’s capillary electrometer, revealed only 2 deflections. Being a physiologist, Waller labeled the waves as one would expect a physiologist to do: he used letters that suggested the anatomic parts of the heart that produced them. Accordingly, he labeled the 2 waves V1 and V2 to indicate ventricular events. Einthoven, …