Heart rhythm disorders London - Arabstoday The way that even low levels of carbon monoxide can be fatal, by disrupting the heart’s rhythm, has been unravelled by researchers in Leeds. They found that levels common in heavy traffic could affect the way the heart resets itself after every beat. Their study in the American Journal of Respiratory and Critical Care Medicine showed a common angina drug may reverse the effect. The British Heart Foundation said the research was a promising start. Carbon monoxide is produced by faulty boilers, cigarettes and car exhausts. It is deadly at high levels as it “shoulder-barges” oxygen out of the blood, meaning less is transported around the body. Carbon monoxide poisoning kills more than 50 people in the UK each year and many more around the world, the BBC reported. However, studies have suggested that even low levels, such as that found in built-up cities with lots of traffic, may also damage the heart. The University of Leeds research team found that the gas kept sodium channels, which are important for controlling the heartbeat, open for longer. Disrupting the sodium channels can disrupt the heart’s rhythm, leading to cardiac arrhythmia, which can be fatal.