Swan, Jeremy (Harold James Charles) (1922–2005), cardiologist, inventor of the Swan–Ganz catheter, was born 1 June 1922 in Sligo town, one of four sons of Harold Swan and his wife Marcelle (née Kelly); both his parents were physicians who had met while studying medicine at UCD. He was christened Harold James Charles, but his mother (who was from Ballymote, Co. Sligo), called him 'Jeremy' and this is how he was generally known. His paternal grandfather William, a printer from Dublin, had married Sara Tynan, sister of Katharine Tynan (Hinkson) (qv). Two of his father's brothers were also doctors, as was one of Jeremy's brothers. When he was a boy Jeremy accompanied his father on his rounds when he attended W. B. Yeats (qv) and Sligo notables.
Education Swan was educated at Killashee School, near Naas, Co. Kildare, before moving to Glenstal Priory School in Co. Limerick (leaving in 1935) and then Castleknock College, Dublin (1935–9). Possessed of an inquisitive and analytical mind, at Castleknock he observed how the pupils arrived at breakfast at varying times after morning mass. This led him to time the duration of each mass, noting 'the variation between priests was high, but within priests low' (Coakley (1996), 200). He was accepted to study medicine at TCD but, following his parents' divorce in 1938, he moved with his mother to London (where she practised until 1968) and studied medicine at St Thomas' Hospital (University of London) (1939–45). When he developed meningococcal meningitis, he was saved by his mother's recognition of the symptoms within six hours; just before he lapsed into a coma she administered sulpha drugs (penicillin being not yet widely available). He recovered well enough to return to his studies and also to box at middleweight during his remaining student years. Qualifying MB in 1945, he was already regarded as prodigious by his classmates. An intern and then junior medical resident, he became a member of the Royal College of Physicians in 1946 (the pass rate for membership was just nine per cent at the time). After six months as a casualty surgeon, he had a two-year stint with the RAF medical service (1946–8), mainly as medical director of one of the military hospitals in Habbaniyah, east of Baghdad, Iraq. With the rank of acting squadron leader, he served on the OC medical command for a time but mainly focused on his medical work, which imbued in him a great appreciation of the role of support and technical staff in medicine.
Initially he intended to return to Ireland and join his father in practice in Sligo, but when Harold Swan died in February 1948 Jeremy turned to cardiovascular physiology. He became a research fellow in physiology at St Thomas' Hospital medical school (1948–51). His Ph.D. (1951), under the renowned physiologists Henry Barcroft (qv) (who had moved from QUB to St Thomas' in 1948) and Sir Henry Dale (Nobel prize winner in 1936 for discoveries relating to chemical transmission of nerve impulses), was awarded for work on cardiac catheterisation and pharmacology in the wider context of the vascular system. Swan and Barcroft (whose research was focused on blood flow to the skin, tissues and muscles) together published a corpus of seminal research papers describing the human vascular response to various treatments and stimulants and co-authored Sympathetic control of human blood vessels (1953), a notable reference work.
Cardiologist In 1950 Swan became lecturer in cardiology at St Thomas', and the following year he moved to the Mayo Clinic, Rochester, Minnesota, USA, initially to take up a two-year research fellowship (1951–3) under Earl Wood, the leading cardiac physiologist. Wood was a pioneer of the emerging field of cardiac catheterisation, and greatly influenced Swan's career, imbuing in Swan the value of rigorous research and intellectual integrity in the search for diagnostic tools and treatments, with continual reference to the underlying biological fundamentals.
Swan's star shone as his diligence and abilities were marked by speedy career advancement. Under a Minnesota Heart Association fellowship (1954–5), he studied biostatistics, electrical measurement and physical chemistry at the University of Minnesota to further his understanding of these complex fields. In 1955 he was appointed consultant physician at the Mayo Clinic and in 1956 he was appointed assistant professor of physiology at the University of Minnesota. Visiting Stockholm in 1959, he familiarised himself with the emerging discipline of cardiac angiography.
On his return to the Mayo, he set up a laboratory investigating angiographic catheterisation and its diagnostic uses and was appointed (1959) director of the cardiology laboratory. His work with John Kirklin, a giant of cardiac radiology and surgery, on developing physiological measurements of cardiac conditions, led him to apply his experience and knowledge to the possible benefits of improving cardiac physiological measurement in clinical settings. He and Kirklin co-authored twenty-six papers (with others) from 1954 to 1965, especially in the journal Circulation. Swan examined methods of measuring heart function and output in pursuit of treatments for anatomical aspects of congenital heart disease, especially the impact of pulmonary hypertension on the surgical outcomes of patients, specialising in the detection of cardiac shunts. His 1954 co-authored paper with Wood and others, 'Pulmonary hypertension in congenital heart disease', published in the American Journal of Medicine, was regarded as a classic.
Exposed to the nascent field of open-heart surgery at the Mayo Clinic, an emerging centre of excellence, Swan specialised further in the physiology of congenital heart disease and by the time he left the Mayo he had published over 100 papers concerning cardiac physiology and allied fields. He brought significant research funding to the Mayo, and was central in developing the first general medical training programme there.
Swan was courted by a range of hospitals and research institutes prior to this appointment in 1965 as director of cardiology at the Cedars of Lebanon Hospital (latterly Cedars-Sinai Hospital) in Los Angeles. Here his pioneering work contributed to the development of both an institutional and personal world-class reputation in cardiology. In his first five years at Cedars he expanded his department (leading the fund-raising efforts that alone facilitated this expansion) from two medics and a secretary to fourteen medics, ten research fellows in cardiology, and fifty allied support staff. Appointed chairman of cardiology (1965), he remained there till his retirement in 1987. He also simultaneously served as professor of medicine (cardiology) at the UCLA school of medicine (1965–86); he retained emeritus status at both institutions after his retirement.
During the 1960s emerging research into heart attacks was often diagnostically reliant on the difficult and risky method of cardiac catheterisation. Here a rigid catheter was fed through a vein in the leg towards the heart, requiring accompanying X-ray imaging to monitor the placement, which limited its application. Swan sought a greater understanding of acute myocardial infarction (coronary thrombosis – also known as 'heart attack') by deploying cardiac catheterisation to ascertain pressure within the heart and surrounding large vessels, which could only be undertaken in a catheterisation lab. A 1964 Lancet paper by a fellow student and former colleague at St Thomas' in the 1950s, Ronald Bradley, detailed how to obtain accurate measurement of pulmonary artery pressure by deploying a catheter composed of fine plastic tubing. However, accurate positioning of the catheter, so as to measure flow pressure, remained a key stumbling block due to both the difficulty of the technique and the limitations of where the technique could be employed.
Swan–Ganz collaboration Swan began development in 1968, with his long-time colleague William Ganz (1919–2009), of what became known as the Swan–Ganz pulmonary artery catheter (PAC) for measuring internal pressure in the heart and surrounding blood vessels. The innovative catheter was inserted through a vein in the neck, shoulder or groin; a balloon at the head of the device directed and carried it through the blood stream to the right side of the heart. During his earlier research in cardiac angiography (radiographic/x-ray examination of the blood vessels), especially for the detection of paediatric congenital heart lesions, Swan realised the limitations of this technique in providing up-to-date and accurate cardiac diagnostics for the critically ill, due to its use for the most part being limited to the catheterisation laboratory.
The genesis of his ground-breaking advancement was, according to Swan, derived from watching the wind propel a sail boat on Santa Monica Bay just days after he had performed a notably difficult cardiac catheterisation. In Swan's own words: 'I noted a boat with a large spinnaker well set and moving through the water at a reasonable velocity. The idea then came to put a sail or a parachute on the end of a highly flexible catheter and thereby increase the frequency of passage of the device to the pulmonary artery' (Coakley (1992), 223). Swan, already a consultant to Edwards Laboratories (later Edwards Lifesciences), who were developing artificial heart valves and allied devices, explored the concept with them and refined the apparatus with Ganz. The feasibility of using 'sails' to carry catheters through the blood stream was explored, though instead they eventually opted for a balloon, which could be deflated upon reaching its destination.
Swan co-authored with Ganz and others a 1970 paper, 'Catheterization of the heart in man with use of a flow-directed balloon-tipped catheter', in the prestigious New England Journal of Medicine, outlining the technique and functionality of this ground-breaking innovation. They described how in 100 consecutive pulmonary catheterisations, sixty patients had successful catheter placement without the aid of fluoroscopy (real-time x-ray of patients' internal workings).
The Swan–Ganz catheter allowed detailed continual analysis and interpretation of a patient's haemodynamics, heart function and capillary pressure in the lungs, as the catheter could remain in place for days, bringing significant clinical benefit. Thus catheterisation could move out of the laboratory and to the bedside. Real-time haemodynamic information was critical, and the Swan–Ganz catheter helped provide this in a critical care context. It helped the treatment of heart attacks, serious burns, acute respiratory problems and many other critical conditions.
During the 1970s its use and deployment soon became standard across a range of critical care specialties as its adoption grew exponentially; the benefits of direct quantitative haemodynamic assessment aided other non-cardiac critical care disciplines. In a few years its use became routine, especially in critical care environments, and by the mid 1980s it was being used on over forty per cent of critical patients. One obituarist noted that 'he became a verb in the hospital: "to Swan" a patient' (New York Times, 14 February 2005).
Ganz, who had grown up on the Czechoslovakian–Hungarian border and graduated from medical school from Charles University, Prague, top of his class in 1947, had made his way to Los Angeles in 1966. Contemporary colleagues noted that Ganz, a senior research scientist, was seen as the more scholarly and research-orientated of the two. He relied on Swan's patronage of his laboratory research while he waited for the necessary permits to practice medicine. Ganz said of Swan: 'Jeremy was a brilliant thinker and organiser; a superb speaker and teacher…His contributions changed medicine, and saved the lives of critically ill patients' ('Edwards Lifesciences pays tribute…').
Together Swan and Ganz had revolutionised intensive surgical intervention and care, providing a deeper understanding of circulatory function in critical patients: allowing safer and accurate real-time analysis of heart function and diagnosis of cardiac conditions, thus assisting bedside analysis and decisions about possible treatments and therapies. By the 1990s over two million Swan–Ganz catheters, licensed to Edwards Laboratories, were sold annually. But from 2000 the technique declined in use, especially in managing heart attacks, as less invasive imaging techniques supplanted its diagnostic function.
In the 1980s and 1990s studies examined the outcomes of those patients on whom the PAC was used, and there was some debate concerning the benefit of its use when balanced against the range of possible side effects. The specific benefits of pulmonary catheterisation to various types of critically ill patients were discussed, and the side effects of its use were balanced with the benefits it brought to bedside diagnosis. But there could be no doubting that Swan's contribution to broader cardiovascular physiology was immense. His innovatory approach, research prowess, and leadership led the way in cardiovascular physiology and haemodynamics research and he is rightly considered to be a true giant of cardiology. The Swan–Ganz catheter 'was truly revolutionary and is the quintessential technology of the intensive care unit' (Bayliss et al).
Honours and awards Swan was widely recognised for his professional achievement, and during his later career, as chair of the Preventative Cardiology Committee of the American College of Cardiology, he undertook work on preventative cardiology; he was a founding member of the editorial board of Preventative Cardiology and associate editor of the Journal of Cardiology. Numerous awards and professional distinctions were bestowed upon him, including the Walter Dixon memorial medal of the British Medical Association; the Maimonides award from Israel; the Theodore Cummings humanitarian award from Cedars-Sinai; the James B. Herrick award from the American Heart Association (1985). He delivered the Stokes lecture to the Irish Cardiac Society (1990), was made an honorary fellow of the RCPI (1994) and was awarded an honorary doctorate by TCD (1996). He was notably proud of these Irish distinctions and made many trips back to Ireland in his latter years, the last in 2002. A member of the American Ireland Fund, he had become an American citizen in 1956.
Swan, who served as President of the American College of Cardiology (1973), was awarded its distinguished fellow award (1985), its distinguished service award (1999), and its highest honour, the distinguished scientific achievement award (2003). He and Ganz were together awarded the American Heart Association's innovation award (2003) for their eponymous catheter.
Swan published over 300 papers while in California, and over 100 textbook chapters. However, despite being best known for his research and innovation prowess, he nurtured and promoted a patient-centric style of medicine. He closely mentored generations of students at Cedars-Sinai, and took a great interest in both their personal and professional development: 'He had the tremendous ability to recognise talent and nurture it. He treated most of the faculty like they were his children' (Lancet obit.).
Retirement Retiring in 1994, Swan moved to Pasadena, and maintained an interest in medicine while indulging his love of gardening. He continued to lecture and write, undertook medico-legal work, and was involved in research into cardiac care devices. In 2001 he suffered a stroke that greatly reduced his mobility, though his speech and cognition were unharmed. He died 7 February 2005, at Cedars-Sinai Hospital in Los Angeles, of complications following a heart attack. His ashes, in accordance with his wishes, were brought back to Sligo.
Swan was survived by six children from his first marriage to Pamela Skeet (the marriage was subsequently dissolved). His youngest daughter, Katherine, predeceased him: a rheumatologist, she died of cancer aged 34 in 1992 and Swan eulogised her in the Annals of Internal Medicine (cxvii (1992), 1,049–50), describing it as 'the best paper I ever wrote' (quoted in Coakley (1996), 207). He married secondly (1973) Roma Shahbaghlian, a presbyterian, and converted to his wife's church; they lived in Beverly Hills before his retirement. With Roma he established a fund for teaching medical ethics to medical students in TCD. The inaugural TCD school of medicine Swan lecture was given on 27 April 2011, as part of the school's tercentenary celebrations, by Professor Raymond Tallis, the renowned physician, philosopher and polymath. The Dr Jeremy Swan Memorial Heart Fund was established at Cedars-Sinai following his death.
Assessment Swan was a pioneering cardiologist who married rigorous and investigative clinical medicine with wide-ranging research interests and committed and engaged teaching and lecturing. Significant not just for his research prowess but also for his guidance of students and his development and successful management of large-scale research programmes, he ranks among the giants of cardiology in the decades following the second world war. The PAC he developed alongside Ganz was ground-breaking in its originality, based on decades of research and medical investigation both in the laboratory and at the bedside. Though somewhat eclipsed in twenty-first century cardiology and critical care, it laid the foundation for the development of less invasive techniques essential in contemporary medicine.