In contrast to William Harvey’s understanding of the pump function of the heart, published in 1628, recognition of the rhythmic function of the heart is traceable to man’s earliest history, including the literature of ancient China and the Bible. Yet only in the 1700s was the wherewithal developed to gain insights into the mechanisms responsible for the heartbeat. Among others, Franklin, Galvani, and Volta planted the seeds of electrophysiology, while Einthoven’s invention of the electrocardiogram in the early 1900s provided the trunk from which the field of arrhythmology could grow. Within a mere 100 years of Einthoven’s invention noninvasive and invasive electrophysiologic diagnostics and therapeutics grew rapidly, expanding into the fields of pharmacology and, especially devices...