The 10 Cardiologists Who Changed the World
Every cardiologist practising today works inside a set of techniques invented by a surprisingly small number of people, most of them within living memory. Before 1929 nobody had put a catheter into a living human heart. Before 1958 nobody had selectively injected a coronary artery. Before 1977 nobody had opened one with a balloon. This is an account of the ten physicians whose work made modern cardiology possible — and a note on why any “top 10 cardiologists in the world” list should be read with caution.
A caveat before the list
There is no authoritative global ranking of cardiologists, and anyone presenting one should be asked who compiled it and on what evidence. Clinical excellence is not measurable across borders in the way that, say, a research citation count is. What can be assessed is contribution: whose work changed what the rest of the specialty does every day.
That is the criterion used here. The list is ordered roughly chronologically rather than by rank, because ranking Forssmann against Grüntzig is a category error — one made the other possible.
1. Werner Forssmann (1904–1979) — the first cardiac catheterisation
In 1929, a 25-year-old German surgical trainee named Werner Forssmann became convinced that a catheter could be passed safely into the human heart. His superiors forbade the experiment. He performed it on himself.
Forssmann anaesthetised his own left antecubital fossa, introduced a ureteric catheter into his vein, advanced it 65 centimetres, then walked downstairs to the radiology department and photographed it sitting in his right atrium. He was dismissed from his post for it.
He spent most of his career as a urologist in a provincial German town. In 1956, nearly three decades later, he shared the Nobel Prize in Physiology or Medicine with André Cournand and Dickinson Richards, who had built the diagnostic discipline of cardiac catheterisation on the foundation he laid. Every catheter procedure performed anywhere in the world descends from that afternoon.
2. André Cournand (1895–1988) and Dickinson Richards (1895–1973) — catheterisation as a science
Working at Bellevue Hospital in New York through the 1940s, Cournand and Richards took Forssmann’s demonstration and turned it into physiology. They measured cardiac output, right heart pressures and pulmonary artery haemodynamics in living patients, establishing the normal values against which every abnormal reading is still compared.
Their work made catheterisation diagnostic rather than merely daring. It is the reason a cardiologist today can say a pulmonary artery pressure is elevated and know what that means.
3. Willem Einthoven (1860–1927) — the electrocardiogram
Einthoven’s string galvanometer, developed in Leiden around 1901, weighed several hundred kilograms and required cooling water and five operators. It also produced the first reliable recordings of the electrical activity of the human heart, and Einthoven named the deflections P, Q, R, S and T — nomenclature unchanged for over a century.
He received the Nobel Prize in 1924. The ECG remains, more than a hundred years on, the single most-performed cardiac investigation on earth and the first test done for chest pain in every emergency department.
4. Mason Sones (1918–1985) — selective coronary angiography, by accident
In October 1958 at the Cleveland Clinic, Mason Sones was performing an aortic root injection when the catheter slipped into the patient’s right coronary artery and 30 millilitres of contrast went directly into the vessel. The prevailing belief was that this would cause fatal ventricular fibrillation.
The patient’s heart stopped. Sones shouted for a scalpel, intending to open the chest — and the patient, asked to cough, restored his own rhythm. He survived.
Sones understood immediately what had happened: the coronary arteries could be imaged selectively and safely with small contrast volumes. Coronary angiography, and therefore the entire field of coronary revascularisation, begins at that moment. Melvin Judkins subsequently designed the pre-shaped catheters — still called Judkins left and right — that made the technique reproducible by ordinary operators.
5. René Favaloro (1923–2000) — coronary artery bypass grafting
An Argentine surgeon who had spent twelve years as a rural general practitioner before retraining, Favaloro standardised saphenous vein bypass grafting at the Cleveland Clinic in 1967. Before him, surgery for coronary disease was improvised and rarely durable. After him, CABG became the most-performed cardiac operation in the world.
Favaloro returned to Argentina at the height of his international standing to build a cardiovascular institute and training foundation there. He took his own life in 2000 amid the institute’s financial collapse during Argentina’s economic crisis — a fact worth recording, because the history of medicine is usually told without its costs.
6. Christiaan Barnard (1922–2001) — the first human heart transplant
On 3 December 1967 in Cape Town, Barnard transplanted the heart of Denise Darvall into Louis Washkansky. Washkansky lived eighteen days before dying of pneumonia, immunosuppressed beyond his ability to fight it.
The operation was widely criticised as premature, and in a technical sense the critics had a point — the surgical technique had been developed largely by Norman Shumway and Richard Lower at Stanford. What Barnard demonstrated was not a new operation but that the thing could be done at all in a human being. Transplantation became survivable in the 1980s with ciclosporin, but the question of whether to attempt it had been settled in 1967.
7. Åke Senning (1915–2000) and Rune Elmqvist (1906–1996) — the implantable pacemaker
In 1958 at the Karolinska Institute, engineer Rune Elmqvist built a pacemaker in a shoe-polish tin and surgeon Åke Senning implanted it into Arne Larsson, a 43-year-old man with complete heart block having up to thirty Stokes-Adams attacks a day.
The first device failed after three hours. The second lasted two days. Larsson went on to receive 26 devices over his lifetime and died in 2001 at the age of 86 — outliving both the surgeon and the engineer who saved him.
8. Michel Mirowski (1924–1990) — the implantable defibrillator
Mirowski, a Polish-born physician who survived the Holocaust as a teenager and trained across four countries, conceived the implantable cardioverter-defibrillator after a colleague and mentor died suddenly of a ventricular arrhythmia.
The idea was dismissed as unworkable and, by some prominent cardiologists of the day, as irresponsible. He persisted, and the first human ICD implant took place at Johns Hopkins in 1980. Sudden cardiac death, previously simply fatal, became a condition that could be treated by a device the patient carried inside them.
9. Andreas Grüntzig (1939–1985) — coronary balloon angioplasty
Grüntzig built his first balloon catheters on his kitchen table in Zurich, using his wife’s hairdryer and materials bought at hardware shops, after colleagues told him the concept was unworkable. On 16 September 1977 he dilated a proximal LAD stenosis in a 38-year-old insurance salesman named Adolf Bachmann, who was awake throughout.
When Grüntzig presented four cases at the American Heart Association meeting in Miami later that year, the audience reportedly stood. Percutaneous coronary intervention — now performed several million times a year worldwide — dates from that single procedure. Bachmann’s vessel remained patent for the rest of his life.
Grüntzig died in a plane crash in Georgia in 1985, aged 46, flying himself back from a weekend away. Julio Palmaz’s balloon-expandable stent, which solved the abrupt-closure and restenosis problems that limited plain balloon angioplasty, arrived shortly after his death.
10. Eugene Braunwald (born 1929) — modern cardiology as a discipline
Braunwald fled Vienna with his family as a child in 1938. He has spent the subsequent eight decades doing more or less everything: defining the haemodynamics of hypertrophic cardiomyopathy, demonstrating that infarct size could be limited rather than merely observed, leading the TIMI trials that established thrombolysis and antithrombotic therapy in myocardial infarction, and editing the textbook that carries his name and that most cardiologists on earth have read.
He remains academically active in his nineties. If any single person can be said to have shaped what cardiology is as an intellectual discipline rather than a set of procedures, it is Braunwald.
Honourable mentions
- Bernard Lown (1921–2021) — DC cardioversion, and a Nobel Peace Prize in 1985 for International Physicians for the Prevention of Nuclear War.
- Alain Cribier (1945–2024) — performed the first transcatheter aortic valve implantation in 2002, creating structural interventional cardiology.
- Michael DeBakey (1908–2008) — Dacron grafts, ventricular assist devices, and the surgical repair of the aorta.
- Salim Yusuf (born 1952) — the INTERHEART and PURE studies, which established that nine modifiable risk factors account for most of the global burden of myocardial infarction.
- Julio Palmaz (born 1945) — the balloon-expandable stent that rescued angioplasty from its own restenosis problem.
What the list tells you about assessing a cardiologist today
Read together, these careers share features that are worth applying when you are assessing any cardiologist — including your own.
They published their failures. Sones described a cardiac arrest he caused. Senning’s first two devices failed within days. The willingness to present a complication to a critical audience is the single most reliable marker of a serious operator, and it is why case presentation at international meetings matters more than an award nobody can trace.
They were rejected by their seniors. Forssmann was sacked. Mirowski was told the ICD was irresponsible. Grüntzig was told balloons would not work. Institutional standing at the time tells you little.
None of them appeared on a “top 10” list during the work that mattered. Forssmann was a provincial urologist for twenty-seven years before the Nobel committee found him.
Which is the practical point. When you are choosing a cardiologist for a specific problem, the useful questions are about volume in your lesion type, willingness to refer to surgery, availability of haemodynamic support and intravascular imaging, and whether the operator submits their work to peer scrutiny. A ranking, especially a self-declared one, tells you none of that.
Frequently asked questions
Who is considered the father of interventional cardiology?
Andreas Grüntzig, for performing the first coronary balloon angioplasty in Zurich in September 1977. Werner Forssmann is generally credited as the father of cardiac catheterisation for his 1929 self-experiment, and Mason Sones with founding coronary angiography in 1958.
Who performed the first heart transplant?
Christiaan Barnard, in Cape Town, South Africa, on 3 December 1967. The patient, Louis Washkansky, survived eighteen days.
Is there an official ranking of the world’s best cardiologists?
No. No recognised medical body publishes a global ranking of individual cardiologists. Lists presented as such are compiled by publishers or directories using undisclosed criteria, and frequently involve payment for inclusion. Assess a cardiologist on procedural volume in your specific condition, use of intravascular imaging, access to circulatory support, willingness to obtain a surgical opinion, and peer-reviewed or conference-presented work.
Who invented the pacemaker?
The first implantable pacemaker was built by engineer Rune Elmqvist and implanted by surgeon Åke Senning in Stockholm in 1958. Earlier external pacing devices were developed by Paul Zoll and others in the 1950s.
Reviewed by Dr A M Thirugnanam, MD, FSCAI, MSICP, Senior Interventional Cardiologist. Last reviewed: September 2026. For an account of contemporary complex coronary intervention, see Dr A M Thirugnanam, senior interventional cardiologist in Hyderabad.
