Former Prime Minister Dr Mahathir Mohamad was in stable condition after his second heart bypass operation today, his daughter said. Marina Mahathir told reporters that her 82-year-old father spent between four and five hours on the operating table, and that the procedure went as planned. "We feel very good, we feel very relieved," she said, adding that Mahathir had been transferred to the intensive care unit. "There was no big drama. I would like to thank all those who prayed for my father's recovery." Mahathir, who ruled Malaysia for more than two decades, was admitted to Kuala Lumpur's National Heart Institute for elective surgery on Sunday after suffering two heart attacks in the past year. He last appeared in public on Friday, waving the Malaysian flag as part of the country's celebrations marking 50 years since independence from Britain. Mahathir led Malaysia for 22 years before handing power to the current premier Abdullah Ahmad Badawi in 2003. Despite retiring from office, Mahathir remains an influential figure in Malaysian politics, and has become an outspoken critic of his successor, accusing him of nepotism and corruption. The former prime minister was rushed to hospital in May after suffering a heart attack, his second in a year after a mild episode in November. Mahathir previously had bypass surgery in 1989.