Dr Dirckx is quite correct that technical developments were critically important in making the electrocardiograph clinically relevant.1-3 His last suggestion is an intriguing one. While the radiographer and the electrocardiographer were not the same person at the Pennsylvania Hospital, studies comparing the organization of radiology and electrocardiography departments in hospitals that did and did not combine the two roles would add a great deal to our understanding of early 20th century American hospitals.The preeminent position of The Johns Hopkins Hospitals has long been recognized by historians of medicine.4I am not surprised to hear that this institution purchased new instruments and adopted new forms before hospitals such as the Pennsylvania Hospital, a well-respected institution, but not one in the same class as Johns Hopkins. However, medical historians of recent decades have tried to move beyond chronicling priorities, a task primarily of interest for those chronicled.
Howell JD. Early Use of X-ray Machines and Electrocardiographs at the Pennsylvania Hospital-Reply. JAMA. 1986;256(11):1445-1446. doi:10.1001/jama.1986.03380110050020