Perspective Article
Manel Ballester-Rodé
Abstract
Over a century ago a Dutch physician, Willem Einthoven, developed a galvanometer that could record the voltages produced during the cardiac cycle using electrodes placed on the body surface. Einthoven assigned the letters P, Q, R, S and T to the various deflections, a terminology that is still in use today. His seminal discovery eventually led to the clinically useful field of electrocardiography, and Einthoven received the Nobel Prize in Medicine in 1924.