Do dysfunctional carotid bodies underlie a form of heart failure

Comparing the mechanistic role of carotid bodies in human heart failure with and without preserved ejection fraction (Dr Katrina Hope)

The carotid body is a cluster of sensors near to the carotid artery in the throat. It is highly sensitive to reduced blood flow and reduced oxygen circulation, and triggers hyperventilation and increased blood pressure by activating an arm of our nervous system called the sympathetic nervous system. Dr Emma Hart is supervising a BHF Clinical Research Training Fellowship that is looking at the role of the carotid body in people with heart failure with preserved ejection fraction (HFpEF). This is where people with heart failure appear to have hearts that can pump normally according to current tests, but they experience difficulty breathing and are unable to exercise. HFpEF comprises around 50% of all heart failure cases, but the mechanisms underlying the condition aren’t known. Dr Hart believes that the carotid bodies may not function properly in HFpEF, and that this could cause an overdrive of the sympathetic nervous system, which is known to worsen heart failure. In this project the fellow will measure the activity of the sympathetic nervous system in people with heart failure, will look at the effects of inactivating the carotid bodies, and how alterations in nerve activity affect heart function, blood vessel relaxation or contractility. They are also looking at whether inactivating the carotid body increases tolerance to exercise. The results will reveal whether the carotid body is a potential target for new treatments for people with this type of heart failure.