Legs, vital clues in heart failure

Doctors tend to treat heart muscles when the organ reels under an attack, overlooking the condition of the legs, which could provide vital clues in treating the condition, new research says. Heart failure causes breathlessness and fatigue that severely limits normal daily activities such as walking. A University of Leeds research team has, for the first time, shown that leg muscle dysfunction is related to the severity of symptoms in heart failure patients, the Journal of Applied Physiology reports. "Many chronic heart failure patients complain of leg fatigue during exercise and this can prevent them from being active," says Harry Rossiter, of the Faculty of Biological Sciences at the university. "Our study shows that by warming up properly, patients can improve the oxygenation and performance of their leg muscles, which is beneficial in promoting exercise tolerance," he adds. In a series of experiments with chronic heart failure patients, the research team measured responses of the heart, lungs and leg muscles following a moderate exercise warm-up, according to a statement from the university. Using a near-infrared laser to measure the oxygenation of the leg muscles, they found that warm-up exercise increased the activity of skeletal muscle enzymes that control energy production. However, this adaptation was less in patients with the most severe symptoms, showing that the heart failure condition had a negative impact on the normal function of the leg muscles. "When your muscles don't use oxygen well, it causes an uncomfortable burning sensation during activity," says Klaus Witte, cardiologist in the team. "The effect of a warm up is to direct oxygen to the places that are going to need it, and make the muscles ready to use it when you start exercising," Witte adds. "Our main message is that exercise is safe and beneficial in patients with heart failure. By warming up the leg muscles properly, the exercise can be more comfortable and sustained for longer - affording great benefits for these patients," Rossiter says.