When leading cardiologist and hypertension researcher, John Raftos, was asked by his children during his 85th birthday celebrations to jot down his lifetime recollections so they could better understand their background, he started with a quote from Dante's Inferno: "Fatti non fasti per vivere come le bestie, Ma per seguire virtute e conoscienza" (You were not made to live like the beasts, But to seek virtue and knowledge).

It was more than apt that Raftos, who died aged 87, was born in 1922 into the squalor of the Sydney slum neighbourhood that was then Surry Hills, in a house where the only language spoken was Greek and where, as a barefoot urchin, he had to fight the local thugs and bullies to survive being called a then detested "dirty dago". His father, Gerasimos Raftopoulos, asked the neighbours which school would best control and educate his wild five-year-old offspring.

The next day a very reluctant boy was dragged into St Francis Catholic School in Albion Street. Having learned all his English in the gutter, Raftos let fly when a nun ordered him into class, calling her "a f---ing old bitch". He was expelled on the spot.

Raftos's father migrated from the island of Ithaca, at the age of 16, in 1898, driven by the extreme poverty on the island. When his first wife died during the influenza epidemic of 1919, he returned to Ithaca and then came back to Sydney in 1920 with his new bride. They moved into Campbell Street, Surry Hills, and John Raftos, the first of their four children, was born there. Gerasimos Raftopoulos (known as Jerry Raftos) ran Mason's Cafe near Central Station.

His three-bedroom terrace house, which still stands, was home to up to 15 people. It had no electricity until 1919 and no radio until 1936.

After his falling out with Rome, Raftos was sent to Crown Street Public School and his abilities were quickly recognised. He was shifted to the Woollahra Demonstration School, the first "opportunity" school in Sydney, and was dux in 1933 and 1934. At Sydney High, as well as excelling academically, he captained the cricket team and was a sprinter in the athletics team. In later years he said he had learned to run fast just to avoid the older bullies in the alleys of Surry Hills.

Raftos enrolled at the University of Sydney to study medicine but his life was still far from comfortable. He slept, year round, on the balcony of his parents' terrace with a sheet of canvas between him and the street.

Graduating at the end of World War II, Raftos became a clinical assistant at Sydney Hospital but in 1948 went to work for the United Nations Relief and Rehabilitation Administration as the medical superintendent of refugee camps near Naples - this experience provided the foundation for his remarkable understanding of patients and students in later life.

Before leaving for Italy, Raftos married Patricia Adamson, whom he met while at university. They had three children: John Robert, Julia and David.

Raftos rejoined Sydney Hospital, then a 350-bed teaching hospital and acknowledged as Sydney's finest medical facility, and started Australia's first high blood pressure clinic there in 1954 and the first coronary care unit. He also maintained a private practice in Macquarie Street specialising in hypertension and coronary heart disease.

He was instrumental in the development of revolutionary treatments using anti-hypertension drugs, including betablockers. A world expert in the field, he published widely in international medical journals. He was made a life member of the High Blood Pressure Council of Australia and he was appointed a Member of the Order of Australia in 1991 for his "services to medicine, particularly in the field of hypertension and cardiology".

He was appointed president of Sydney Hospital in 1978 and immediately found himself in a titanic struggle with Neville Wran's government. Wran wanted to shut the hospital and move its operation to Sydney's booming western suburbs. Raftos argued that the almost half million people who worked in the CBD each day needed expert medical care as much as anyone in the suburbs. At that stage St Vincent's and the Prince of Wales hospitals were nothing like the centres of excellence they are today.

Raftos lost his fight with Wran but not before he organised a protest demonstration calling for the hospital's retention that saw 40,000 people pack Macquarie Street outside both Parliament House and Sydney Hospital. After the downgrading of Sydney Hospital, Raftos moved to St Vincent's where he was the director of coronary care until he retired.

During his time at Sydney Hospital Raftos also lectured medical students at the University of Sydney in cardiology and hypertension. His clarity and precision in teaching made him the favourite tutor for medical students but his dry humour, uncompromising manner and his ability to swear like a Surry Hills garbo kept them in awe.

Raftos and Patricia divorced in 1972 and he later married Calliope (Poppy), with whom he spent the remainder of his life. When forced in his 50s to give up competition cricket, he took to golf and played regularly at The Australian and later Royal Sydney. He played in the Wednesday competition until a month before his death - although he said making "a bloke of 87" play off the back tees was "sadistic".

He is survived by Poppy and his three children.