As 20th-century medicine advanced, despite the electrocardiogram and improved understanding of basic cardiovascular physiology, quantifiable chemical details about the way the heart works—in both health and disease—were long in coming.
An extraordinary series of experiments by Dickinson Richards and André Cournand in the 1940s, just as heart disease began to spike in industrialized countries, brought unprecedented precision to the diagnosis of heart and circulatory disease. With a research program that adapted an old tool (the catheter) and a hypermodern instrument (the fluoroscope), Richards and Cournand were able to make unprecedented measurements of blood flow from within the heart itself. Viewing the heart, lungs, and pulmonary circulation as an integrated system, they developed descriptions of hemodynamics that led to a new taxonomy of heart disease.
Work at the pulmonary-coronary laboratory at Bellevue, the first of its kind in the world, overcame beliefs about invasive procedures and the human heart and opened the way to a wide variety of diagnostic and therapeutic uses for catheterization, including angiography, angioplasty, and stent implantation. With Werner Forssmann, Cournand and Richards were awarded the Nobel Prize in 1956.