Understanding factors that make exercise difficult for people with heart failure

Objective assessment of fatigue or dyspnoea as the mechanism of exercise limitation in heart failure: Implications for individualised therapy

People who have heart failure can sometimes find it difficult to carry out day-to-day activities because they experience breathlessness or leg tiredness. This means they may have difficulty with exercise, and they are sometimes said to have ‘low exercise capacity’. The gold-standard measure of exercise capacity is to measure the maximum amount of oxygen consumed during exercise on a treadmill or bike. But these tests do not show whether exercise capacity is limited by breathlessness or by leg tiredness. It’s important to be able to distinguish between these factors, to help people with heart failure receive the best treatment. In this project, Dr Ferguson will use a new test that can measure the force generated by the leg muscles during an exercise. This will determine whether exercise capacity is low in individual heart failure patients because of breathlessness or leg tiredness. They will then give patients a drug to reduce breathlessness and investigate the effects on their exercise capacity. Dr Ferguson expects the drug to increase exercise capacity only in patients limited by breathlessness and have no effect on people whose exercise is limited by leg tiredness. They hope to demonstrate that the test can be used to personalise treatments for people with heart failure.