Apart from there being no surgical staff or facilities at the 'National Heart Hospital', there was another powerful reason why operating on the heart could be discounted there. It was its senior physician Frederick Price, who was the editor and writer on cardiology of one of the most authoritative textbooks [3]. In the 1920s there had been some surgery for mitral stenosis, with ten cases on record. Seven of these were operated on by the same Eliot Cutler in Boston. After an encouraging first survivor, his subsequent patients all died with hours or days. The era closed with Cutler, a realist and successful surgeon, writing in 1929, a "final report" [4]. Price described this experience in subsequent editions of his text book [3] but in successive later editions, he hardened his line against surgery viewing it to be at best first experimental and then firmly contraindicated. This was aligned with the teaching of the time. But Brock knew that Harken's experience had refined the approach to reaching within the heart.
Brock also knew of the single but notable success in 1925 of Souttar who freed the commissures rather than cut the mitral valve leaflets. The patient lived for about seven years, clinically improved to a degree, to be feted by Royalty. Another more fortunate coincidence helped Brock's ambition to achieve effective heart surgery. Wartime collegiality in the allied forces medical services led to an exchange programme between Johns Hopkins and Guy's.
Maurice Campbell, senior cardiologist and editor of the British Heart Journal, saw many children with cyanotic heart disease and there was nothing he could do but to give a gloomy prognosis to their parents [5]. Thanks to the work of Helen Taussig and Vivien Thomas, Blalock had already performed the systemic to pulmonary artery shunt operation in hundreds of children and brought his proven and successful operation to Guy's during September 1947.
Brock and Campbell formed the Club bringing together cardiologists, surgeons, anaesthesiologists, radiologists, and most importantly the clinical scientists of the Medical Research Council unit who, in collaboration with colleagues in Boston and Baltimore, developed and refined catheterisation techniques to obtain better and safer anatomical and functional diagnosis of cardiac malformations.
Brock wrote
"Intracardiac surgery is not for the lone worker. Team work is essential. To give one example, at Guy's there is a group of some 15 people actively engaged in the work, and as time passes we find that more and more are drawn into the team" [6]. Those 15 were the core group of the Club, developing and practicing integrated cardiology. The total tally of those who attended and visited from Britain, Europe and all over the world is more than 80. Their story is told in "The Heart Club" [1].

1. Treasure T: The Heart Club. ed 1st, London/New York, Clink Street, 2017.
2. Harken DE: Foreign bodies in, and in relation to, the thoracic blood vessels and the heart. Surg Gynecol Obstet. 1946;83:117-125.
3. Price F: A Textbook of the Practice of Medicine. ed 3rd, London, Oxford University Press, 1929.
4. Cutler EC, Beck CS. Present status of surgical procedures in chronic valvular disease of the heart; final report of all surgical cases. Arch Surg. 1929;18:403-416.
5. Campbell M: Congenital Heart Disease. Guy's Hospital Gazette 1946;50:150-156.
6. Brock RC. Discussion on the surgery of the heart and great vessels. Proc R Soc Med. 1951;44(12):995-1003.