Scientists have captured images that show, for the first time, bleeding inside the heart after a heart attack, which can indicate how much damage has occurred, according to a study published in the January issue of Radiology.

The researchers, from the MRC Clinical Sciences Centre at Imperial College London, said the hope is that this kind of imaging will be used alongside other tests to create a more complete picture of a patient's condition and their chances of recovery.

Recently, research has shown that some people experience bleeding inside the heart muscle once blood starts to pump into it again after a heart attack. However, the significance of the bleeding is currently not understood.

For this small study, using MRI, the researchers captured images of bleeding inside the heart in 15 patients from Imperial College Healthcare NHS Trust, who had recently suffered a heart attack. Analysis of the scans revealed that the amount of bleeding correlated with how much damage the heart muscle had sustained.

Patients with damaged heart muscle after suffering a large heart attack experienced more bleeding into the heart muscle, compared with those whose heart attack was relatively small. The researchers were able to detect the area of bleeding because of the magnetic effects of iron present in the blood.

"Using [MRI] shows us that patients who develop bleeding inside their damaged heart muscle have a much poorer chance of recovery. We hope that this will help us to identify which patients are at most risk of complications following their heart attack,” said Declan O'Regan, MD, the first author of the study from the MRC Clinical Sciences Centre.

The Medical Research Council, the British Heart Foundation and the Department of Health, United Kingdom, funded the research.