The Sphygmomanometer and its Impact on Clinical Practice

The following post is a paper written by Haylie Helms (@HaylieHelms), a junior majoring in Biology, Society, and Environment at the University of Minnesota, in the spring semester of 2015 for Dominique Tobbell’s class HMED 3075.  In a recently published pair of articles in the Bulletin of the History of Medicine, Dominique Tobbell and Lois Hendrickson described  their use of historical artifacts (from the Wangensteen Historical Library) in their history of medicine courses.  Ms. Helm’s paper is the third of three papers offered as examples of the work students have done in their classes.

Introduction

Blood, and its circulation throughout the body, has been studied for thousands of years. The earliest recorded writings about the circulatory system can be found in the Ebers Papyrus, an ancient Egyptian manuscript, dating back to 1500 BCE.[1] The Egyptians acknowledged the presence of mtw, which can be roughly translated to vessels that transport blood and nutrients throughout the body.[2] The understanding of how the blood circulated remained a highly debated topic throughout much of the 17th century. Although William Harvey, an English physician, is credited with the discovery of blood circulation in 1628, most physicians of the time believed that the lungs were responsible for moving the blood.[3] Once the connection between heart rate and pulse was discovered, it was then possible to determine blood volume and blood pressure.[4] Blood pressure was measured for the first time by Stephen Hales in 1733.[5] Hales placed a brass tube into the crural artery of a mare and connected to it a glass tube that was nine feet long.[6] By calculating how high the blood rose, Hales was able to calculate the blood pressure. It was not until nearly a century later that blood pressure was accurately studied. Early methods of studying blood pressure in humans followed the same technique.  The first noninvasive blood pressure measurement tool, called a sphygmomanometer, was invented in 1881 by Samuel Siegfried Karl Ritter Von Basch.[7]

I will examine the introduction of the sphygmomanometer into medical practice using Roger’s sphygmomanometer from the Wangensteen Historical Library of Medicine. In particular, upon the invention of the sphygmomanometer, how were the physicians’ understanding of heart health altered? In what ways did the invention of the sphygmomanometer impact clinical diagnoses? Lastly, how did the user of the sphygmomanometer change from when it was first introduced in practice in 1881 until the 1930s? It is hypothesized that the invention of the sphygmomanometer alone did not change the physician’s understanding of heart health. It was in unison with many other areas of research that the field of cardiology and pathology progressed. As a result of the progression of clinical diagnostics, the user shifted from the scientist to health promotion companies. No longer was it solely the physician who ordered for blood pressure to be measured; the general public was requesting it as well. Therefore, the invention of the sphygmomanometer set the stage for a deeper understanding of heart anatomy and disease for both physicians and the general public alike.

The Von Basch Sphygmomanometer

Early methods for measuring blood pressure required glass tubes filled with mercury to be inserted into the artery of the patient. The invasiveness of the procedure limited the feasibility of these devices to be used as a diagnostic tool. Von Basch’s 1881 noninvasive sphygmomanometer, however, used a rubber ball that was placed over the radial artery to suppress the pulse.[8] The rubber ball was filled with water and connected to a mercury tube.[9] When the pulse was no longer felt, the reading on the mercury tube indicated the systolic blood pressure.[10][11]

M0017687 Samuel Siegfried von Basch: Sphygmomanometer
Figure 1: Samuel Siegfried von Basch: Sphygmomanometer. Wood engraving Down’s surgical instrument catalogue Published: 1906. Welcome Library.

 

Von Basch went on to measure 100,000 patients’ blood pressure over the span of ten years using his sphygmomanometer.[12]  He concluded that the normal blood pressure was between 135 and 165 mmHg.[13] He also noted instances when patient’s blood pressures were abnormal and their current symptoms or diagnosis. Through his work, Von Basch identified the equivalent of today’s hypertension, which he called latent atherosclerosis, and cardiac hypertrophy.[14]

Although the Von Basch sphygmomanometer was safe for patients and provided accurate clinical data, it was not widely used by physicians.[15] Dr. Scipione Riva-Rocci stated, “It is not surprising that despite the many persistent attempts to introduce sphygmomanometry into medical practice, this has remained nothing more than a luxury measurement or an unusual investigation.”[16] Most physicians of the time preferred old techniques such as using the pressure from their hands to restrict flow.[17] The British Medical Journal published their view that sphygmomanometers “pauperizes the senses and weakens clinical acuity.”[18]  It was not just the sphygmomanometer that was under scrutiny; many physicians and scientists of the time were opposed to many new technologies at the turn of the century. Upon the introduction of the x-ray machine into clinical practice in 1895, physicians preferred to use their hands to make diagnosis.[19]

The Introduction of the Modern Blood Pressure

In 1896 Dr. Scipione Riva-Rocci published his method of measuring blood pressure.[23] Riva-Rocci’s method placed a 5 cm band around the patient’s arm and inflated it using a bulb filled with air.[24] The cuff was inflated until the pulse was no longer detected; like the Von Basch sphygmomanometer, the value recorded was the systolic pressure.

sphyg2
Figure 2: Riva-Rocci-type sphygmomanometer, originally developed in 1896.[25] Wangensteen Historical Library of Medicine.
In 1901 Von Recklinghausen found a crucial flaw in Riva-Rocci’s system; the band was too narrow.[26] This resulted in an acute angle that would form between the cuff and the skin. Coincidentally, it caused local areas of high pressure buildup, which skewed the pressure reading.[27] Von Recklinghausen fixed the problem by simply widened the band to 12 cm.[28] The sphygmomanometer with the wider band provided accurate and safe blood pressure readings that could be used for clinical diagnostics and research. However, this method only allowed for the measurement of the systolic blood pressure and not the diastolic pressure.

In order to measure both the systolic and diastolic pressure, the oscillometric technique, which was created in 1876, was paired with the sphygmomanometer.[29] Under the oscillatory blood pressure method, the user would use the Riva-Rocci method while watching the oscillations transmitted to the mercury in a manometer.[30] When the cuff pressure was equal to the arterial pressure the compressed artery would throb causing small fluctuations in the cuff pressure.[31] The fluctuations would transition from small to large oscillations identifying the diastolic pressure.[32]

The Riva-Rocci method plus the oscillatory method would be modified once more to acquire the basic method of blood pressure measurement seen today. In 1905 Russian surgeon Dr. Nikolai Korotkoff identified the difference in sound between the systolic and diastolic pressures.[33] Using a stethoscope, Dr. Korotkoff was able to hear tapping sounds, which he explained as the blood flowing back into the artery.[34] Known as the Korotkoff sound, the slight difference in the way blood pressure was recorded changed the way physicians viewed the device. Initially, many physicians were opposed to sphygmomanometers because they believed it took away their reliance on their senses and weakened clinical acuity. By requiring the physicians to listen for the sound, it brought back the prestige of the method since only those trained could properly acquire and interpret data. The Korotkoff sound set the stage for future cardiologists to uncover the underlying pathology.[35]

The Impact of the Sphygmomanometer

Physicians in the late 1890s understood the effects of the vessels and heart on blood pressure: blood pressure is controlled by the constriction and dilation of blood vessels and the frequency and stroke volume of the heart.[36]  Riva-Riccoi warned physicians of the usefulness of the sphygmomanometer during clinical diagnosis.

Therefore, if all aspects of the problem were like this [multiple factors affecting the blood pressure], and only like this, sphygmomanometry would not have any clinical applications. The data it supplied would only give us abstract information of purely academic interest, but nothing that could be used on patients or for learning the course of a morbid process.[37]

Many researchers studied the usefulness of blood pressure readings over the next decades in order to uncover its usefulness. Common studies included finding trends associated with patient size, temperature, position (sitting, standing, and laying), age, occupation, diet, sleep, time of day, alcohol and tobacco, mental state, exercise, external temperature, atmospheric pressure, and menstruation.[38] Despite all of the research conducted, the data sphygmomanometers collected was still not very useful in clinical diagnostics for pathological diseases.

Like all current knowledge of symptoms and disease, discoveries were made based on repeated exposure and documentation. When patients had abnormal blood pressures that could not be explained, physicians documented their symptoms and the course of their illness. For example, arterio-sclerosis was diagnosed with the aid of the sphygmomanometer and the observation of thickening of superficial arteries, signs of enlarged left ventricle, and the “ringing aortic second sound.”[39]

As time went on, and more correlations were found between symptoms, vitals, and diagnoses, physicians began to uncover the usefulness of the sphygmomanometer in clinical practice. In 1910 Dr. Janeway argued that the sphygmomanometer was most valued in diagnosing hypertension.[40] Physicians understood the effects and dangers of hypertension. Dr. Janeway wrote,

Hypertension is not merely a symptom of diagnostic and prognostic value, nor is it to be considered only as an effect of causes acting on the heart and vessels. It is of itself a source of altered function throughout the circulatory system, which leads to further secondary changes. These cannot in all cases be clearly separated from the primary changes producing the high pressure, but they may frequently be distinguished anatomically as well as theoretically.[41]

As compared to an x-ray machine that can be used as the sole diagnostic tool when determining if a bone is broken, the sphygmomanometer alone cannot be used to diagnose a patient. Mental state, temperature, diet, exercise, and sleep all must be considered as physicians understood the effect they can have on blood pressure.[42] As displayed in Dr. Janeway’s writings, upon the introduction of the sphygmomanometer into clinical practice, the physician’s understanding of heart pathology was further developed. The device itself did not change the physicians understanding of heart health; it set the foundation for further medical discoveries.

The Evolution of the User

The sphygmomanometer is a technology closely related to the thermometer’s history of invention, development of knowledge, introduction to practice, and evolution of the user.[43] The sphygmomanometer was initially sold to the physician or clinical researchers with the mindset that the sphygmomanometer could only be operated by someone with extensive training in the sciences.[44] It was believed that only those with a scientific background could properly acquire precise data and interpret the results. The device itself was not hard to use, however. As one physician wrote, “after all, no mysterious nor difficult [technique] is involved in sphygmomanometry, as the study of blood pressure may be correctly termed.”[45] Nonetheless, the prestige associated with the user upon the invention of the sphygmomanometer made it acceptable for only those who were trained extensively in the sciences, such as physicians or researchers, to operate it.

As physicians became more aware of the associations between blood pressure and heart pathology, there was an increase in demand for the sphygmomanometer. Blood pressure, measured by the sphygmomanometer, became a standard vital taken on patients by the 1910s.[46] Dr. Satterthwaite wrote, “No physical examination is complete without a record of the blood pressure. It is also very helpful in the diagnosis and management of cardiovascular and renal diseases and toxemias.”[47] In addition, heart health became a topic of discussion in local newspapers. Columns written by doctors explained what blood pressure is, how it is measured, and the importance of monitoring it.[48] Ads urged patients to be more aware of their heart health and to actively monitor their blood pressure. “Your high blood pressure can be measured. The sphygmomanometer registers it with absolute accuracy.”[49] Other ads in the newspaper used fear to urge patients to be more aware of their blood pressure: “He closed the door behind him and walked down the stairs in a kind of a daze, the doctor’s words ringing in his ears: ‘High blood pressure.’  ‘You may die any time – you can’t live over three years.’”[50]  “Arterio-sclerosis. Recent knowledge of the disease from which Paul Morton died.”[51]

As the demand for the sphygmomanometer increased at a rapid rate, physicians were inundated with blood pressure requests. Like the thermometer, physicians began to realize that measuring blood pressure was tedious and repetitive.[52] To ease the strain on physicians, nurses were needed to use the sphygmomanometer; the modern hospital depended on the invention of the ‘thinking nurse.’[53] As Margarete Sandelowski outlined, the ‘thinking nurse’ was necessary for quantification of clinical signs and symptoms.[54] Nurses were needed to carry out physicians’ orders and have knowledge to record, interpret, and report information vital to diagnosis and treatment.[55]

The user evolved once more; after the nurse was qualified to operate the sphygmomanometer, health promotions companies began utilizing the sphygmomanometer. Health insurance companies utilized the sphygmomanometer to promote healthy living and screen future customers for life threatening diseases. Some companies required a blood pressure evaluation prior to granting insurance coverage.[56] Other companies used the sphygmomanometer to attract customers: “For your own sake and for the sake of those you love and who are dependent on you, you should investigate the Witter Water Treatment.”[57] “When the sphygmomanometer, before your eyes, shows that your pressure has been reduced, there is no chance of error. We get, in the majority of cases, a marked reduction in pressure after one treatment.”[58] Although treatments such as the Witter Water Treatment were not scientifically proven, and likely ineffective, they brought the sphygmomanometer to the attention of the public. Patients were now approaching their physician for blood pressure measurements. These actions by patients, and outside organizations, aided in the shift of medicine at the turn of the century to a scientific, evidenced based, system.[59]

Conclusion

The invention of the sphygmomanometer alone did not change the physician’s understanding of heart health. It was in unison with many other areas of research that the field of cardiology and pathology progressed. The work of many scientists, including but not limited to Von Basch, Riva-Rocci, and Korotkoff, laid the foundation for future cardiologists and pathologists. Symptoms were recorded in addition to blood pressure readings to properly diagnose patients. Initially the blood pressure readings could only be obtained by the physicians as there was a belief that the physician was the only one scientifically inclined enough to record and interpret the data. However, as blood pressure became a standard of practice, and patients began to request blood pressure readings, the physicians were inundated with the tedious task of testing the blood pressure. To alleviate the strain on the physicians, nurses were trained to take the blood pressure. The ‘thinking nurse’ led to the increased efficiency in the hospital and a more scientific based approach in diagnostics. In addition, the routine use of the sphygmomanometer led to a shift in knowledge surrounding heart anatomy and disease from physician to public. Newspapers ran advertisements to inform the public of the importance of getting regular blood pressure readings. Other organizations, such as insurance companies, understood the dangers of high blood pressure and required customers to receive a blood pressure test before they could receive insurance. Prior to the invention of the sphygmomanometer routine tests in the clinical setting were not possible due to the invasiveness of the procedure. Therefore, the invention of the sphygmomanometer set the stage for a deeper understanding of heart anatomy and disease for both physicians and the general public alike while aiding in the shift of the hospital to a greater scientific approach in the turn of the century.

Bibliography

“Display Ad 11.” Los Angeles Times, August 4, 1923.

“Display Ad 451.” Los Angeles Times, February 4, 1923.

American Diagnostic Organization. “History of the Sphygmomanometer.” Accessed November 11, 2015.

Barr, Justin. “Vascular Medicine and Surgery in Ancient Egypt.” Journal of Vascular Surgery 60, no. 1 (2014): 260-263.

Booth, Jeremy A. “A Short History of Blood Pressure Measurement.” Proceedings of the Royal Society of Medicine 70, no. 11 (1977): 793-799.

Detroit Pharmaceutical Co., Catalogue of Physician’s Supplies: Including drugs and chemicals, dispensing supplies, pharmaceuticals, surgical instruments, electric apparatus, trusses and appliances Michigan: Aldine Printing Works, 1894.

Evans, Dr. W.A. “How to Keep Well: Blood Pressure.” Chicago Daily Tribune, June 28, 1914.

Faught, F.A. Blood-Pressure Prime. Philadelphia: .P. Philling & Son, 1914.

Howell, Joel. Technology in the Hospital: Transforming Patient Care in the Early Twentieth Century. Baltimore: Johns Hopkins University Press, 1995.

Janeway M.D., Theodore Caldwell. The Clinical Study of Blood Pressure. New York: D. Appleton and Company, 1910.

Kotchen, Theodore A. “Historical Trends and Milestone in Hypertension Research: A Model of the Process of Translational Research.” Journal of Hypertension 58 (2011): 522-538.

Middleton, Dr. William S. “Blood Pressure Determination: A Nursing Procedure.” The American Journal of Nursing 30, no. 10 (1930): 1219-1225.

Noyes, Bradford. “The History of the Thermometer and the Sphygmomanometer.” Bulletin of the Medical Library Association 24, no. 3 (1936): 155-165.

Ogedegbe, Gbenga. “Principles and Techniques of Blood Pressure Measurement,” Cardiology Clinics 28, no 4. (2010): 571–586.

Riva-Rocci, Dr. Scipione. “A New Sphygmomanometer.” Gazzetta Medica di Torino 47, no. 50 (1896): 981-996.

Sandelowski, Margarete Devices and Desires: Gender, Technology, and American Nursing. Chapel Hill: The University of North Carolina Press, 2000. 21-43

Satterthwait, Dr. Thomas E. Cardio-vascular Diseases: Recent advances in their physiology, diagnosis, and treatment. New York City: Lemcke and Buechner, 1913.

Science Museum Brought to Life, Exploring the History of Medicine. “Bloch Type Sphygmomanometer, Paris, France, 1881-1913.” Accessed December 7, 2015.

Soto-Perez-de-Celis, Enrique. “Karl Samuel Ritter Von Basch: the Sphygmomanometer and the Empire.” Journal of Hypertension 25, no. 7 (2007): 1507-1509.

Tracy, Dr. S.G. “Arterio-Sclerosis: Recent Knowledge of the Disease from which Paul Morton Died.” The Washington Post, January 25, 1911.

 Endnotes

[1] Justin Barr “Vascular Medicine and Surgery in Ancient Egypt.” Journal of Vascular Surgery 60, no. 1 (2014): 260.

[2] Barr, “Vascular Medicine and Surgery in Ancient Egypt,” 261.

[3] Jeremy A Booth “A Short History of Blood Pressure Measurement.” Proceedings of the Royal Society of Medicine 70, no. 11 (1977): 793.

[4] American Diagnostic Organization. “History of the Sphygmomanometer.” (accessed November 11, 2015).

[5] Booth, “A Short History,” 794.

[6] Booth, “A Short History,” 794.

[7] Enrique Soto-Perez-de-Celis.”Karl Samuel Ritter Von Basch: the Sphygmomanometer and the Empire.” Journal of Hypertension 25, no. 7 (2007): 1507.

[8] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1507.

[9] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1508.

[10] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1508.

[11] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1508.

[12] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1508.

[13] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1508.

[14] Soto-Perez-De-Celis, “Karl Samuel Ritter Von Basch,” 1508.

[15] Theodore A. Kotchen, “Historical Trends and Milestone in Hypertension Research: A Model of the Process of Translational Research.” Journal of Hypertension 58 (2011): 522.

[16] Dr. Scipione Riva-Rocci, “A New Sphygmomanometer.” Gazzetta Medica di Torino 47, no. 50 (1896): 985.

[17] Science Museum Brought to Life, Exploring the History of Medicine. “Bloch Type Sphygmomanometer, Paris, France, 1881-1913.” (accessed December 7, 2015).

[18] Kotchen, “Historical Trends and Milestone in Hypertension Research,” 522.

[19] Joel Howell, Technology in the Hospital: Transforming Patient Care in the Early Twentieth Century, (Baltimore: Johns Hopkins University Press, 1995), 103-132.

[20] Riva-Rocci, “A New Sphygmomanometer,” 984.

[21] Riva-Rocci, “A New Sphygmomanometer,” 983-984.

[22] Riva-Rocci, “A New Sphygmomanometer,” 989.

[23] Booth, “A Short History,” 797.

[24] Riva-Rocci, “A New Sphygmomanometer,” 985.

[25] Riva-Rocci, “A New Sphygmomanometer,” 985.

[26] Booth, “A Short History,” 797-798.

[27] Booth, “A Short History,” 797-798.

[28] Booth, “A Short History,” 798.

[29] Gbenga Ogedegbe, “Principles and Techniques of Blood Pressure Measurement,” Cardiology Clinics 28, no 4. (2010): 572.

[30] Booth, “A Short History,” 798.

[31] Booth, “A Short History,” 798.

[32] Booth, “A Short History,” 798.

[33] Booth, “A Short History,” 798

[34] Booth, “A Short History,” 798

[35] Booth, “A Short History,” 798.

[36] Riva-Rocci, “A New Sphygmomanometer,” 989.

[37] Riva-Rocci, “A New Sphygmomanometer,” 989.

[38] Theodore Caldwell Janeway M.D., The Clinical Study of Blood Pressure. (New York: D. Appleton and Company, 1910), 108-127.

[39] Janeway, The Clinical Study of Blood Pressure, 143.

[40] Janeway, The Clinical Study of Blood Pressure, 137.

[41] Janeway, The Clinical Study of Blood Pressure, 148.

[42] Janeway, The Clinical Study of Blood Pressure, 108-127.

[43] Bradford Noyes, “The History of the Thermometer and the Sphygmomanometer.” Bulletin of the Medical Library Association 24, no. 3 (1936): 155-165.

[44] Detroit Pharmaceutical Co., Catalogue of Physician’s Supplies: Including drugs and chemicals, dispensing supplies, pharmaceuticals, surgical instruments, electric apparatus, trusses and appliances (Michigan: Aldine Printing Works, 1894).

[45] Dr. William S. Middleton, “Blood Pressure Determination: A Nursing Procedure.” The American Journal of Nursing 30, no. 10 (1930): 1219.

[46] Dr. Thomas E. Satterthwait. Cardio-vascular Diseases: Recent advances in their physiology, diagnosis, and treatment. (New York City: Lemcke and Buechner, 1913), 40.

[47] Satterthwait, Cardio-vascular Disease, 40.

[48] Dr. W.A. Evans, “How to Keep Well: Blood Pressure.” Chicago Daily Tribune, June 28, 1914, A4.

[49] “Display Ad 11.” Los Angeles Times, August 4, 1923, 7.

[50] “Display Ad 451.” Los Angeles Times, February 4, 1923, X123.

[51] Dr. S.G. Tracy. “Arterio-Sclerosis: Recent Knowledge of the Disease from which Paul Morton Died.” The Washington Post, January 25, 1911, 6.

[52] Noyes, “The History of the Thermometer and Sphygmomanometer,” 155-165.

[53] Margarete Sandelowski, Devices and Desires: Gender, Technology, and American Nursing (Chapel Hill: The University of North Carolina Press, 2000), 21-43.

[54] Sandelowski, Devices and Desires, 21-43.

[55] Sandelowski, Devices and Desires, 21-43.

[56] F.A. Faught, Blood-Pressure Prime. (Philadelphia: G.P. Philling & Son. 1914).

[57] “Display Ad 451,” X123.

[58] “Display Ad 11,” 7.

[59] Howell, Technology in Modern America, 30-68.

Electrocardiogram and Diphtheria in the early 20th Century

The following post is a paper written by Matthew Cohen, a senior majoring in Biology, Society, and Environment at the University of Minnesota, in the spring semester of 2015 for Dominique Tobbell’s class HMED 3075.  In a recently published pair of articles in the Bulletin of the History of Medicine, Dominique Tobbell and Lois Hendrickson described  their use of historical artifacts (from the Wangensteen Historical Library) in their history of medicine courses.  Mr. Cohen’s paper is the first of three papers offered as examples of the work students have done in their classes.

The electrocardiogram’s ability to observe the conduction of the heart, changed medical practice for diphtheria in the early 20th century. My paper will argue that the implementation of the electrocardiogram by physicians changed the diagnosis, monitoring and treatment of diphtheria infected patients in American from 1900-1938. I will be using the electrocardiogram from the Wangensteen historical library collection. This paper will discuss how the electrocardiogram functions, and the implications and clinical relevance of using the electrocardiogram to diagnose the infectious disease diphtheria.

ecg2

To understand the impact and effects of the electrocardiogram, it must first be defined as a medical technology. The electrocardiogram (ECG) is a medical technology that is used to record the electrical signals of the heart. According to Joel Howell’s definition of technology, the ECG is medical technology by virtue of being a physical object, the activity it performs, and the technological know-how needed to use it.[1] The ECG is relatively easy to use and produces an accurate recording of the heart’s electrical signals however, the scientific know-how to understand the results is what makes the ECG a medical technology. The information recorded by the ECG must be interpreted by a person skilled to equate the physical tracing to the physiological functions of the heart. This means that an anatomical and physiological understanding of the heart is required to accurately understand the results.

The heart has two main components that must be considered, the physical heart and its electrical system. The heart is a muscle, comprised of specialized cardiac cells which, under the influence of an electrical current, contracts to force blood throughout the body.[2] The heart has four anatomically distinct regions. The upper portion of the heart is divided into two openings called the atria and the lower portion of the heart is divided into two openings called the ventricles. These openings are filled with blood, which is expelled from the heart to the body during systolic contracting. This is the physical pumping system of the heart, which must work in conjunction with the electrical system.

The coordinated contraction of the atria and ventricles is controlled by the heart’s electrical system. The ECG records this electrical current, which is a representation of the heart’s physical functioning. The electrical signal passes through a well-established pathway inside of the heart. Cardiac tissue has unique properties, which allow it to generate its own electrical impulses. These electrical impulses, under normal cardiac function, originate in a specific cluster of cardiac cells, called the Sinoatrial (SA) node. The electrical impulses then travel via the intra atrial pathway to the Atrioventricular (AV) node.[3] This results in the contraction of the left and right atria. The electrical impulse then travels through the bundle of His and down the purkinje fibers, resulting in the contraction of the left and right ventricle.[4] This is the normal pathway of the heart’s electrical activity, called a normal sinus rhythm. Since all cardiac cells have the potential to generate an electrical impulse, abnormal conductive pathways can also occur.

The invention of the ECG is credited to Willem Einthoven in 1901.[5] Einthoven developed the standardized ECG pattern, which displayed the electrical pathway discussed previously. Einthoven’s work led him to develop the 3 limb lead placement, now known as precordial leads. The 3 limb lead placement creates an equilateral triangle which is used to capture the hearts electrical activity and is still used today.[6]

The essentials of the electrocardiogram have remained largely unchanged since its development. Einthoven’s early ECG was enormous- weighing over 600 pounds, required two rooms and five people to operate.[7] Einthoven’s ECG measured fluctuation in electrical current in a wire that was suspended between electromagnetics.[8] The results were recorded onto a photographic plate. The electrocardiogram in the Wangensteen historical library collection was made by the Cambridge Instrument Company and it was given the name “Simpli-Scribe Portable Model”.[9] This ECG was designed to be portable, with an exterior made of wood and a metal carrying handle.[10] This version of the ECG did not have a date of manufacture but Cambridge produced the Simpli Scribe from 1945-1960.[11] The Simpli Scribe is approximately one foot cubed in size, and is powered by a two prong electrical cord. The five leads on the ECG are attached to the patient via a strap placed on the chest. The resulting electrical fluctuations are recorded by an electrically heated metal needle that scorches the reading into the paper.[12] While the Simpli-Scribe, is smaller and more refined than the earliest electrocardiogram’s designed by Einthoven, the basics still remained unchanged. Both required electromagnets, recorded fluctuation in electrical activity, and used wires attached to a patient at the same locations.

The use of the ECG in recording cardiac activity was well known by the mid 1910s. The electrocardiogram was hailed as an unquestionable way to determine if one was sick or well.[13] The clinical application of the ECG for monitoring cardiac rhythms such as auricle fibrillation and extra systole beats were well documented.[14] In 1916, the British army adapted the electrocardiogram as a means to screen army recruits, in conjunction with X-rays, to determine their cardiac health and fitness to serve.[15] By this time period, the ECG was already recognized for its ability to determine cardiac health. The electrocardiogram was so prevalent, that by 1924, Willem Einthoven was awarded the Nobel Prize for Physiology and Medicine for his discovery.[16] While the electrocardiogram was well known for its ability to record the heart’s electrical activity, its use in medicine during the time was limited to routine physical exams.  However, the importance of the ECG changed when the electrocardiogram was used to monitor and diagnose cardiac issues in infectious diseases such as diphtheria.

Diphtheria is an infectious disease caused by the bacteria Corynebacterium diphtheriae that is spread from person to person through respiratory droplets.[17] The disease targets the mucus membranes of the mouth and nose where they can travel to the respiratory system.  Diphtheria will produce symptoms similar to a common cold, such as weakness, sore throat and low grade fever.[18] A thick coating will build up in the mouth and nose, making it difficult to breathe. While these respiratory symptoms cause difficulty breathing, the majority of deaths associated with diphtheria are the result of the toxin produced by the bacteria.[19] The diphtheria toxin (DT) can travel into the blood stream, where it will damage internal organs such as the heart, lungs and kidneys.[20] The damage caused to the heart is called myocarditis. Myocarditis is an inflammation of the heart tissue, which results in mortality as high as fifty percent if left untreated in patients.[21]

Diphtheria was a widespread infectious disease in the United States in the early 20th century. In 1921 there were 206,000 confirmed cases of diphtheria which resulted in 15,520 deaths.[22] The population of the United States in 1921 was 108,538,000 according to the United States Census Bureau.[23]  This means that 0.18% of the U.S. population in 1921 was infected with diphtheria. There was still a strong prevalence of diphtheria in the U.S., even after the introduction of a vaccine in 1923.[24] The vaccine provided an effective means of prevention but treatments for the afflicted remained the same. The strong presence of diphtheria is shown by specialized hospital wards dedicated to diphtheria patients, fifteen years after the vaccine was introduced.[25]

By the mid to late 1920s the effects of the diphtheria toxin on the neuro-musculature and fatty degeneration of the heart were well known, and understood by physicians to be longer lasting than previously thought. Jenner Hoskin, a doctor at the Philadelphia Hospital conducted a study on the effects of diphtheria on the heart in 1926. Hoskin discovered that upon admission to the hospital, 72% of patients had no cardiac complication with the exception of tachycardia, but several days later 28% of patients were found to have abnormal pulses which degenerated into grave heart trouble.[26] While it was not clear what Hoskin defined as “grave heart trouble” the implications were clear; diphtheria had deadly effects on the heart. Hoskin noted that virtually all patients admitted for diphtheria initially had tachycardia that persisted for 36-48 hours after initial treatment was given.[27] The continued presence of tachycardia following the first 36-48 hours was an indication of myocarditis, a result of the diphtheria toxin damaging the heart.[28] Hoskin’s use of persistent tachycardia over the treatment interval was common practice at the time. Hoskin argues for the importance of electrocardiograms in identifying myocarditis secondary to diphtheria and monitoring the patient’s heart even after their hospital stay.[29] Close monitoring of the heart can result in early recognition of cardiac complications and reduce mortality rates. Physicians in the early 20th century recognized that death as a result of diphtheria typically occurred on the 10th day of infection from acute myocarditis, or on the 3rd week from fatty degeneration of the heart muscle.[30] This highlights the importance of having an effective way to monitor the cardiac function of the heart, which the electrocardiogram does effectively.

Prior to the wide spread use of the ECG in monitoring heart function, a physician would assess heart health through auscultation of the heart, palpation of pulses, physical appearance of the patient and subject statements from patient.[31] Auscultation of cardiac sounds using the stethoscope was the preferred method.[32] The physician would listen to cardiac sounds at specific points on the chest to determine the health of the patient’s cardiac valves. The strength of the heart would also be assessed by feeling the pulse, typically at the wrist, to determine the regularity and strength of the heart.[33] The physical appearance of the patient was noted, pallor or a pale appearance was considered a sign of poor perfusion and attributed to cardiac insufficiency.[34] These assessments were subjective and depended on the knowledge of the individual physician to be able to identify these abnormalities.

Even in patients that survived the disease, lasting cardiac abnormalities were found. Cardiac abnormalities such as premature beats, diminished cardiac reserve, heart enlargement and tachycardia were observed. Hoskin stated that the lasting effects of diphtheria on the heart can be seen in the “slurring of the Q.R.S. complex” visible on ECG.[35] The Q.R.S. complex represents the depolarization of the ventricles and the corresponding contraction. Cardiac abnormalities that resulted from the infection would need to be monitored over the patient’s life to ensure detection of worsening cardiac issues. Hoskin stated that it is of the “utmost importance that patients in whom cardiac symptoms and abnormalities have been discovered be thoroughly examined both clinically and electrocardiographically” and that these examinations must continue until it is resolved or reaches a stable condition.[36] The ECG can be utilized to monitor and diagnose diseases that have an impact on the heart but are not cardiac in nature, such as diphtheria. Diphtheria may have no effect on the electrical conduction system of the heart, but it will result in physical changes to the heart tissue which can be seen on the ECG tracing, such as Q.R.S. complex slurring.

The shift in prevalence of the ECG in cardiac monitoring can be seen in a 1938 article by Mason Leete in which he states it is “presumptuous to enter such a field [diphtheria] armed only with fingers, stethoscope and sphygmomanometer.”[37] This displays an attitude shift during the late 1930s in which the subjective information gathered by the physician decreased in importance and the objective information created by medical technology such as the ECG increased in significance.  The importance of the ECG in heart health was noted but traditional measures of obtaining pulses, heart sounds and more recently blood pressures were still valued.[38] The combined use of subjective information obtained by the physician and unbiased technologically obtained data, such as from the electrocardiogram and sphygmomanometer, are valued as the most effective way to monitor patient’s disease progress. A careful comparison of clinical and electrocardiographic findings are required to thoroughly assess the patient’s health and provide an accurate prognosis.[39]

In treating diphtheria and monitoring the progress of infected patients, the use of the electrocardiogram became the standard. The importance of the ECG in diphtheria patients is emphasized in Harries’s 1932 article titled “Auxiliary treatment of toxic Diphtheria, when he states that “obtaining repeat electrocardiograms from the cases under treatment . . . provid[es] the most valuable evidence as to progress.”[40] This statement displays the value placed on ECG’s in diphtheria patients as the most valuable tool to monitor progress, even over the physical observations of the physician. This shift in preference is mirrored in a 1935 article on electrocardiogram in diphtheria in which the author states that “although there is much agreement between electrocardiographic and clinical signs the former usually proceeds the later and change in the curves may demonstrate lesions which cannot be discovered by other means.”[41] This is an important shift from years prior when the ECG was seen as the primary tool for not only monitoring patients but also diagnosing previously unseen or unobservable lesions of infection. The instrument is sensitive enough and its accuracy is trusted to the point that the information displayed by the ECG is more accurate than what the physician can observe. The importance of the ECG was shown in an 1937 article by Norman Begg in which he states that “Survival depends upon the amount and distribution of undamaged or lesser damaged myocardial tissue,” the severity of which could be determined by the ECG.[42] The value of the ECG to monitor the patient’s progress and prognosis was well known by this time period, but the ECG also influenced treatment of diphtheria.

The medicine used to treat diphtheria remained relatively unchanged from 1899 to the late 1930s. Early treatment of diphtheria consisted of the use of antitoxin for the diphtheria bacteria, although the dosages varied significantly based on the preference of the physician providing care.[43] Additionally, the use of mercurial was advocated for, which was mercury in a solution, generally in a topical form placed on to the lesions of infection and oxygen therapy as needed to treat difficulty breathing.[44] There is no mention of using electrocardiograms to monitor cardiac health. This picture changed dramatically in the mid 1920s with the prevalence of the ECG. While many of the medicines used to treat diphtheria remained unchanged, such as the use of antitoxin, the use of digitalis became prevalent to control the tachycardia that resulted from the diphtheria toxin.[45] This led to the prevalence of the ECG as a tool to determine when certain medicines are indicated to treat the patient.

The electrocardiogram was also important in its influence on treatments given to diphtheria patients. The ECG was used to determine the extent of cardiac toxicity from the diphtheria infected patients and excluded the use of certain drugs, that in milder cases of diphtheria would have been indicated. Digitalis is an example of when an ECG would be used to rule out the use of digitalis for that patient due to cardiac damage.[46] The drug digitalis is well known for its effects on decreasing heart rate, increasing strength of contractions, and increasing blood pressure.[47] Digitalis was generally indicated for use to treat tachycardia in moderate to severe diphtheria infections, determined by electrocardiograph, was contraindicated due to its increased cardiac demand.[48] The ECG was used to not only determine abnormal conduction of the heart but also as a clinical tool to determine if a medicine such as digitalis is safe for the patient.

The ECG was widely used in monitoring diphtheria patients and had a strong influence on treatments rendered. The cases of diphtheria rapidly decreased in the late 1940s with the widespread use of the diphtheria vaccine, even though the vaccine was developed in 1923.[49]  After the 1940s, the prevalence of diphtheria dropped sharply from approximately 19,000 in 1945 to 1 in 1998.[50] The diphtheria vaccine resulted in the eradication of new cases of the disease in the United States. The treatment for those infected, with the addition antibiotics such as penicillin in the late 1940s, remains the same.[51]

In conclusion, the electrocardiogram had widespread use in the medical field as a tool for assessing cardiac function. The utilization of the electrocardiogram in monitoring cardiac condition had profound impacts on the diagnosis and treatment of diphtheria during the early 20th century.  The ECG became the standard for assessing the severity of infected patients, monitoring their progress, determining patients’ prognosis and which medicines could safely be used. The success of the ECG in diphtheria infected patients redefined the ECG as a medical technology for diagnosing infectious diseases as well as cardiac diseases. The ECG is currently used to monitor a wide variety of infectious diseases including HIV, rubella, typhoid, rheumatic fever and diphtheria.[52] The electrocardiogram changed medical practices in diphtheria and is still actively used in infectious disease care today.

Bibliography

Primary Sources:

Andersen. “The electrocardiogram in diphtheria” The Lancet (1935) 689.

Begg, Norman “Diphtheritic Myocarditis, an electrocardiographic study” The Lancet (1937).

Harries, E. “Auxiliary treatment of toxic diphtheria” The Lancet (1932).

“Heart Diagnosis in British Army.” New York Times (1916).

Hoskin, Jenner. “The after effects of diphtheria on the heart.” The Lancet (1926), 1141-1143.

Leete, Mason. “The Heart in Diphtheria.” The Lancet (1938).

McClanahan, H. “Treatment of Diphtheria.” The Lancet (1899).

Simpli-Scribe EKG, Wangensteen historical library collection. University of Minnesota- Twin Cities.

“Sure way to finding out how sick or well you are by measuring electricity in your body” The Washington Post (1914).

Williams, James. “Electrocardiogram in Clinical Medicine.” American Journal of the Medical Sciences (1910) 644-668.

Williamson, Bruce. “The rational use of Digitalis.” The Lancet (1928).

Secondary Sources:

Anatomy of the Heart National Heart, Lung and Blood Institute, National Institute of Health (November 2011), accessed November 22, 2015.

Barold, S.S. “Willem Einthoven and the birth of clinical electrocardiography a hundred years ago.” Cardiac Electrophysiology Review (2003): 99-104.

“Definition of Penicillin History” MedicineNet (2012).

Diphtheria Centers for Disease Control (2013).

“Historical National Population Estimates.” United States Census Bureau (2000), accessed November 22, 2015.

Howell, Joel, D. Technology in the Hospital, Transforming patient care in the early twentieth century (Baltimore: Johns Hopkins University Press, 1995), 9

Nalmas, Sandhya. “ Electrocardiographic Changes in  Infectious Diseases” Hospital Physician (2007), 3.

“Simpli-Scribe” Edward Hand Medical Heritage Foundation, accessed November 22, 2015.

Vaccine, Diphtheria Center for Disease Control, accessed November 22, 2015.

 

Endnotes

[1] “Anatomy of the Heart” National Heart, Lung and Blood Institute National Institute of Health (November 2011) accessed November 22, 2015.

[2] “Anatomy of the Heart” National Heart, Lung and Blood Institute

[3] “Anatomy of the Heart” National Heart, Lung and Blood Institute

[4] “Anatomy of the Heart” National Heart, Lung and Blood Institute

[5] S.S. Barold, “Willem Einthoven and the birth of clinical electrocardiography a hundred years ago.” Cardiac Electrophysiology Review (2003), 99-104.

[6] “Anatomy of the Heart” National Heart, Lung and Blood Institute

[7]  “Simpli-Scribe.” Edward Hand Medical Heritage Foundation, accessed November 22, 2015.

[8] “Simpli-Scribe.” Edward Hand Medical Heritage Foundation

[9]  Simpli-Scribe EKG, Wangensteen historical library collection. University of Minnesota- Twin Cities.

[10] Simpli-Scribe EKG, Wangensteen historical library collection.

[11] “Simpli-Scribe.” Edward Hand Medical Heritage Foundation

[12] “Simpli-Scribe.” Edward Hand Medical Heritage Foundation

[13] “Sure way to finding out how sick or well you are by measuring electricity in your body” The Washington Post (1914)

[14] James Williams, “Electrocardiogram in Clinical Medicine.” American Journal of the Medical Sciences (1910), 644-668.

[15] “Heart diagnosis in British army.” New York Times (1916), 21.

[16] Barold, “Willem Einthoven”, 99-104.

[17] Diphtheria Centers for Disease Control (2013) accessed November 22, 2015.

[18] Diphtheria

[19] Diphtheria

[20] Diphtheria

[21] Diphtheria

[22] Diphtheria

[23] “Historical National Population Estimates.” United States Census Bureau (2000), accessed November 22, 2015.

[24] Diphtheria

[25] Diphtheria

[26] Jenner Hoskin, “The after effects of diphtheria on the heart.” The Lancet (1926), 1141.

[27] Hoskin, “The after effects of diphtheria on the heart.”, 1142.

[28] Hoskin, “The after effects of diphtheria on the heart.”, 1142.

[29] Hoskin, “The after effects of diphtheria on the heart.”, 1142.

[30] Hoskin, “The after effects of diphtheria on the heart.”, 1142.

[31]  Mason Leete, “The Heart in Diphtheria.” The Lancet (1938)

[32]  Leete, “The Heart in Diphtheria.”

[33]  Leete, “The Heart in Diphtheria.”

[34]  Leete, “The Heart in Diphtheria.”

[35]  Hoskin, “The after effects of diphtheria on the heart.”, 1142.

[36] Hoskin, “The after effects of diphtheria on the heart.”, 1143.

[37] “The Heart in Diphtheria.”

[38] “The Heart in Diphtheria.”

[39] “The Heart in Diphtheria.”

[40] E. Harries, “Auxiliary treatment of toxic diphtheria” The Lancet (1932).

[41] Andersen “The electrocardiogram in diphtheria” The Lancet (1935), 689.

[42]Norman, Begg. “Diphtheritic Myocarditis, an electrocardiographic study” The Lancet (1937).

[43] H. McClanahan, “Treatment of Diphtheria.” The Lancet (1899).

[44] McClanahan, “Treatment of Diphtheria.”

[45] Bruce Williamson, “The rational use of Digitalis.” The Lancet (1928).

[46] Williamson, “The rational use of Digitalis.”

[47] Williamson, “The rational use of Digitalis.”

[48]  “The Heart in Diphtheria.”

[49] Vaccines Center for Disease Control, accessed November 22, 2015.

[50] Vaccines

[51] “Definition of Penicillin History” MedicineNet (2012), accessed November 22, 2015.

[52] Sandhya Nalmas, “ Electrocardiographic Changes in  Infectious Diseases” Hospital Physician (2007), 3.

Teaching History of Medicine with Artifacts and Oral Histories

The next issue of the Bulletin of the History of Medicine contains a new section on pedagogy.  This inaugural section contains two articles, one on teaching medical history with artifacts (by Dominique Tobbell) and the other on teaching medical history using oral histories (by Lois Hendrickson).  In addition to the print articles, Professors Tobbell and Hendrickson are publishing on this blog three student papers that illustrate more concretely the kinds of work students produce in their courses.  These papers will be published as separate blog posts in the first week of April.

What follows is a preview of the articles you can read in the Bulletin later this week, as well as the student papers that will be posted on this blog.

sphyg2
Sphygmomanometer from Wangenstein Historical Library, University of Minnesota.

Students are fascinated with the opportunity to touch history – to use artifacts, skim historical newspapers and archival documents, and listen to first-hand accounts of lived history as presented in oral history interviews.  They glean skills and significantly different perspectives from interacting directly with these primary sources. In their article discussing pedagogical approaches to teaching with archival documents, artifacts and oral history, Dominique Tobbell and Lois Hendrickson outline their methodology and student outcomes in two undergraduate courses in which they collaborated. In the first course, students examine a historical medical artifact from the Wangensteen Historical Library, and situate its impact or change on health care practice, health care institutions, patients, consumers, and health care policy. The second course asks students to use oral histories to understand and reflect on roles that women have played as healers, patients, research subjects, and health activists in U.S. society. Their companion essays examine how they bring resources into the classroom and develop exercises enabling students to work with and analyze various artifacts, texts, and manuscripts, and oral histories.

Three student research papers from the Technology and Medicine in Modern America course provide examples of how these students used historical artifacts and integrated course reading, lectures, and original research, to write about how technology came to medicine’s center-stage, and the impact that medical technologies had on medical practice, medical institutions, and medical consumers. The first essay by Haylie Helms, discusses the impact sphygmomanometers had on clinical diagnosis, its introduction to practice, and the evolution of the user that came with an increase in demand for sphygmomanometery. In a second essay, Maria Nulls details the demise of a technology, the Triangular Bandage. She follows its transformation from a technology used by trained medical practitioners, to a simplified and condensed consumer product, meant for civilian use as seen in Johnson & Johnson’s ‘First-Aid’ Kits.  The final essay, by Matthew Cohen, argues that the implementation of electrocardiograms (ECG) changed the diagnosis, monitoring and treatment of diphtheria. Cohen’s paper attributes this to a shift in the increased significance of objective information created by medical technological, and details how this medical technology redefined diagnosis of infectious diseases as well as cardiac diseases.

ecg2
ECG from Wangenstein Historical Library, University of Minnesota.