“Open Heart: History of Cardiology”
Cardiology is a recent development in the history of medicine. For a long time the heart was an unattainable part of the body, misunderstood in its function and mechanisms, although its vital role was acknowledged. It is by the 19th and 20th century that tools were finally developed to observe its activity and, eventually, treat its ailments. This exhibit explores the medical science behind the human heart starting from the days of William Harvey to the innovations of the 20th century.
The visitors will be invited to learn about cardiology through four different historical characters, William Harvey, René Laennec, Willem Einthoven, John Alexander Hopps, and discover how their innovations helped to create modern cardiology.
The project draws on the collections of the Museum of Health Care and images from the Wellcome library. It presents to the visitor some of the major inventions in the realm of cardiology such as the pacemaker or the defibrillator and illustrates their importance in the evolution of health care.
Following his first experiment in 1816, Réné Laennec started to design a variety of stethoscopes before publishing his findings in 1819. This tube is one of the first models he created. It is made of three pieces of hard wood containing brass tubing, and could be disassembled. Laennec built most of these early models himself.
Many physicians followed the example of Laennec by creating more efficient stethoscopes. All of them experimented with the classical tube model fitting in one ear, but in the 1850s, flexible tubes began to be used, and in 1851 the Irish physician Arthur Leared created the first binaural stethoscope fitting in both ears. This invention was commercialized the following year by George Cammann, who also published a major work on auscultation.
For a long period of Western medical history, a popular remedy prescribed to treat issues related to the heart was bloodletting. Since physicians believed that blood was constantly created and rarely eliminated, they thought that bad blood could affect the body and the heart. Removing this blood was supposed to alleviate or even cure this affliction. This chart dating from the 16th century demonstrates the different points on the body where bloodletting could be done.
Harvey was born in England in 1578 and pursued studies in medicine in Padua in 1599. He eventually became physician to King James I, and was even sent out to investigate cases of alleged witchcraft. In 1628, he published his most famous work De Motus Cordis, or On the Motions of the Heart and Blood, in which he explained his findings on the circulation of blood and on the role of the heart as a pump. His ideas shook centuries of medical knowledge. This plate shows an experiment conducted by Harvey and published in his treatise showing the actions of the arteries and veins, and which blood vessels revealed the presence of valves.
In 1776, a physician by the name of William Withering examined a female patient suffering from dropsy, or edema. Believing there was nothing more to be done for her, he decided to leave but learned later that she had survived by using an old folk remedy of foxglove, a common garden plant. Withering went on to study the effects of the plant for a decade and discovered that dropsy was due to the weakness of the heart and that foxglove could alleviate these symptoms through its action of normalizing heart rhythm. Foxglove, or digitalis, was still very dangerous to use as it is also highly toxic and even fatal if used in high concentration, but its discovery opened the way to new forms of treatments.
Willem Einthoven was the first to successfully build a machine that could record a patient’s pulse through the electrical current generated by the heartbeat. Einthoven was born in Indonesia and grew up in the Netherlands, and began experimenting with electrocardiograms after becoming a professor of medicine in Leiden. In 1901, he created a machine that used a string galvanometer. Every time a current was measured, the string would move through the action of an electro-magnet, the result being imprinted on a roll of photographic paper showing a diagram of the heart’s pulse. The machine was very complex and the patient had to have his hands or feet immersed in salt water jars connected to the machine. This invention launched the field of cardiology.
The principle of defibrillation was first demonstrated around 1899, but the dangers of the procedure slowed progress considerably as the patient’s heart had to be exposed and current applied directly to it. It was only in 1947 that defibrillation was first successfully used on a human patient. Claude Beck, a professor of surgery, was operating on a 14-year-old boy who went into cardiac arrest. After 45 minutes of manual stimulation, the defibrillator finally arrived and was applied to the heart, saving the boy’s life. The following decade saw the development of closed chest and direct current methods, saving the lives of many more.
The first successful pacemaker model was somewhat of an unintentional invention. Dr. Wilfred G. Bigelow and Dr. John C. Callaghan were both working in Toronto on cold heart surgery. They believed that bringing the body into hypothermia would lower the heart rate and enable open heart surgery. To do this they needed a way to keep the heart beating and had the idea of using an electrical current. They enlisted the help of the electrical engineer John Hopps who, in 1949, created an external machine that would regulate the heart beat by an electrical wire going to the heart by way of the jugular. About 10 years later, the first wearable pacemaker was finally implanted in Sweden with great success.