A history of the origin, evolution, and impact of electrocardiography.

The invention of the electrocardiograph by Dutch physiologist Willem Einthoven in 1902 gave physicians a powerful tool to help them diagnose various forms of heart disease, especially arrhythmias and acute myocardial infarction. The discovery of x-rays in 1895 and the invention of the electrocardiograph 7 years later inaugurated a new era in which various machines and technical procedures gradually replaced the physician's unaided senses and the stethoscope as the primary tools of cardiac diagnosis. These sophisticated new approaches provided objective information about the structure and function of the heart in health and disease. This review summarizes the origins and development of electrocardiography and addresses its role in defining cardiology as a specialty.