The head of South Korea's largest business group Samsung underwent an emergency operation Sunday after developing symptoms of heart failure, hospital officials said.
Lee Kun-Hee, 72, was admitted to a hospital near his home in Seoul Saturday night due to a respiratory problem.
He showed symptoms of heart failure and received emergency treatment before being moved early Sunday to Samsung Medical Centre where his problem was diagnosed as "acute cardiac infarction", the hospital said in a statement.
"He is now recuperating in a stable condition after undergoing an operation," it said.
The procedure involved the placement of a stent, a tube inserted to unblock blood vessels, Yonhap news agency said.
Lee is chairman of Samsung Electronics, the group's flagship firm and the world's largest technology company in revenue terms.
He is largely credited with turning Samsung -- founded by his father in 1938 -- into a global brand which is now the world's top chipmaker and smartphone maker.
Lee is also the de facto head of the entire business empire, which employs some 200,000 staff in dozens of affiliates and dominates every aspect of life in South Korea.
Lee underwent lung surgery in the late 1990s and has been suffering from respiratory complications since then.
Due to his medical history, he stays overseas during the winter to prevent respiratory ailments, Yonhap said, adding he returned to Seoul in April after months in the United States.
Lee is South Korea's richest man with a net worth estimated by Forbes magazine at around $10.8 billion and has a son and two daughters.
His son, Jay Y. Lee, 45, serves as vice chairman of Samsung Electronics.
The founding family controls Samsung through a complex web of share cross-holdings in group subsidiaries.
Samsung has reorganised its structure to pave the way for the son's eventual succession to the top post and cement the family's hold over the group.
Jay Lee's sisters also control key posts in group subsidiaries.
Samsung, whose name means Three Stars, began life as a trading company founded by Lee Kun-Hee's father Lee Byung-Chull.
Lee took over after his father's death in 1987.
He stepped down as group chairman in 2008 after being charged with tax evasion but returned as chairman of Samsung Electronics later after receiving a presidential pardon.
Samsung has rapidly expanded its presence in the global smartphone market, dethroning Apple as the world's top smartphone maker amid worldwide patent battles between the tech giants over technology and design.