PEOPLE with diseased hearts are benefiting from an innovative operation using powerful laser beams to cut channels in the heart and improve blood flow. Five men and three women, aged from 57 to 70 and diagnosed with heart disorders, have received transmyocardial laser revascularisation at Grantham Hospital in the past eight months. The latest patient - a 60-year-old man who suffered chest pains for four years - received the laser treatment yesterday and is expected to go home in 10 days. Consultant Dr David Cheung Lik-ching said Grantham had become the first centre in Southeast Asia to perform the surgery. The laser technique was safe even for high-risk patients, he said. It creates channels in the heart wall, boosting blood supply to heart muscles which have become starved by blockages. 'Blood will be able to flow directly from the left ventricular cavity of the heart into the heart muscles through the channels,' said Dr Cheung, senior lecturer of Hong Kong University's Department of Surgery. 'Unlike coronary bypass surgery - which bypasses the obstruction in the coronary arteries with grafts - it is not necessary to stop the heart and put the patient on a heart-lung machine. 'And it takes less time. It requires one to two hours compared to four to six in bypass surgery.' Up to 35 channels, each one millimetre in diameter, are fired by a 1,000-watt carbon dioxide laser through the muscle of the beating heart in the area that has been deprived of blood. The laser is synchronised with the patient's heartbeat and automatically fires when the heart chamber is filled with blood. The blood stops the laser's energy and prevents it from damaging other tissues in the heart. Dr Chow Liang, the hospital's senior medical officer, said doctors needed more time to gauge its effectiveness, but the preliminary results were encouraging. Follow-ups after six months showed few complications. 'The surgery will be a good alternative for Chinese people, whose coronary arteries are often too small and diffusely diseased,' he said. Heart disease is Hong Kong's second biggest killer after cancer.