In 1921, Willem Einthoven invited Thomas Lewis to lecture in Leiden. Lewis responded, “The Leiden visit is one to which I am looking forward with great pleasure. It will be most stimulating to come to the Mecca of electrocardiography …”1 It is with much the same feeling that I approach this lectureship, honoring the memory of the man who, in developing the ECG, in effect ushered in the modern era in electrophysiology. In being here, I also pay homage to the Dutch tradition of electrophysiology, which has flourished since Einthoven’s time. In 1930, several years after Einthoven’s passing, the Russian electrophysiologist Samojloff was invited by Paul Dudley White (later the first Einthoven Lecturer) to reminisce about Einthoven’s contributions. Samojloff stated, “… Einthoven worked almost exclusively in the field of electrophysiology. This branch of physiology stood for a long time completely isolated from life, medicine, and even from the general path of development of physiological knowledge; shut off in this way, electrophysiology could not progress and it seemed that it would be difficult to alter this sad situation of the study of animal electricity. [Einthoven’s mind] … worked like an instrument of precision. He worked only on what could be measured and his measurements reached the limit of precision possible under the circumstances.”2 Einthoven’s string galvanometer was remarkable in the fidelity and accuracy of its recordings and in its utility for interpreting the rhythm and state of health of the heart. Moreover, in applying the instrument to diagnosis, Einthoven foresaw events that wouldn’t occur again for 50 years or more. Not only were patients’ ECGs recorded, but the signals were wired the 1-mile distance from hospitalized patient to laboratory for registration and analysis. The off-site diagnostician was often able to identify a patient’s affliction faster than the on-site physician. …