PRAGUE (Reuters) - Czech President Vaclav Havel‘s health deteriorated overnight, his medical team said on Tuesday, citing an irregular heartbeat and the onset of bronchial pneumonia nine days after he underwent intestinal surgery. Doctors said they were „intensively“ treating the heart problem, the latest in a string of serious ailments to afflict the 61-year-old playwright and former anti-Communist dissident. They said Havel remained on a respirator a day after doctors had to cut a hole in his throat to aid his breathing when his right lung collapsed. „Computer analysis confirmed the initial stages of bronchial pneumonia,“ the doctors said in a statement, adding that Havel had developed „heart arrhythmia in the early morning hours. This situation is being intensively treated at present.“ There was no further comment on the nature of the heart treatment or how serious this latest development may be, but a news conference was expected after the presidential medical team met in mid-afternoon. Havel‘s right lung collapsed after fluid built up from an infection on Sunday night just hours after he had been removed from a respirator. Doctors said in Tuesday‘s statement that an x-ray showed the right lung returning to normal after Monday‘s tracheotomy procedure while the accompanying fever had dissipated. Havel underwent cancer surgery to remove a small lung tumour in 1996 and nearly died from post-operative pneumonia. In April this year his large intestine ruptured while he was on holiday in Austria. Doctors said then that quick work by surgeons in Innsbruck saved his life. Havel, who led the peaceful overthrow of Czechoslovakia‘s Communist government in 1989, had an operation on July 26 to remove a bag bridging a gap in his large intestine. The bag had been inserted when the intestine ruptured in April. Doctors said the intestinal problem was unconnected with the lung cancer. Havel, who has no control over the daily function of the government, has duties which are more ceremonial than executive, although he remains an influential and popular figure in the country and around the world. In January, parliament narrowly vote him another five-year term which the Czech constitution says must be his last.