Trailblazing technology can detect acute pressure changes in heart
Researchers have used cutting-edge imaging technology to measure acute pressure changes inside the heart – work that has also helped them pinpoint why a widely used drug given to help calculate blood flow through the organ causes breathlessness in some patients.
The state-of-the-art technology uses magnetic resonance imaging (MRI) to create detailed pictures of the heart.
Using the new technology, the team from the University of East Anglia in the UK discovered that pressure inside the heart goes up when a specific medication called adenosine is given for testing blood flow.
They also found out why adenosine – which is a naturally occurring substance that relaxes and dilates the blood vessels and is used to help restore normal heartbeats in people with certain rhythm disorders – makes patients breathless during the test.
The team – whose work has been published in the journal BMC Cardiovascular Disorders – say their findings could help doctors better diagnose and monitor patients with heart disease and heart failure.
Lead researcher Dr Pankaj Garg, from UEA’s Norwich Medical School, said: “When patients present with symptoms of heart disease, doctors use a special test called heart MRI to take detailed pictures of the heart and see how well it is working.
“Sometimes, patients are given a special medication called adenosine during the heart MRI test to see how blood flows through the heart, and it can cause breathlessness.
“We wanted to better understand the way that the heart functions, and why patients become breathless when given adenosine.”
The UEA team worked with researchers at the University of Leeds and studied 33 patients referred for a stress cardiac MRI.
This test is performed to help evaluate the blood flow in the heart arteries, looking for blockages.
The research team took pictures of the patient’s heart when it was resting and when it was working hard after being given adenosine.
Dr Garg explained: “Adenosine mimics the effect of exercise on the heart while the patient is lying down on the scanner. And we discovered why it makes patients get out of breath.
Postgraduate researcher Hosamadin Assadi, also from UEA’s Norwich Medical School, added: “We looked at the top chamber of the heart, called the left atrium, and also looked at the lower part of the heart, called the left ventricle.
“We used advanced software to measure and study the heart, and we also estimated the pressures inside the heart before and after giving the medication.
“Our study shows that after giving patients adenosine, the heart’s left atrium got bigger really fast – just before the blood flowed out.
“This is important as it shows that the previously published heart MRI pressure model is adaptable to acute changes in the heart and can be more broadly used to diagnose and monitor heart disease – in particular heart failure.
“We also found that a measure called LVFP, which tells us about the pressure inside the heart, went up when the heart was working hard.”
Dr Garg’s previous work showed that a 4D heart MRI scan can create detailed flow images of the heart, and how this non-invasive imaging technique can measure the peak velocity of blood flow in the heart accurately and precisely.
The scan takes just six to eight minutes and can provide precise imaging of the heart valves and the flow inside the heart in three-dimensions, helping doctors determine the best course of treatment for patients.
“This work strengthens the notion of using heart MRI to measure pressures inside the heart,” Dr Garg said.
