MRI was used to measure oxygen consumption in the legs of heart failure patients by researchers at the University of Texas, who from this noninvasive technique have gained extra insight into different forms of heart failure.

Senior author Mark Haykowsky, led the study published in the journal PLoS One. The team of researchers recruited 10 patients who have high mortality rates. These participants were older heart failure patients with either big, dilated hearts, or big,  stiff hearts that are unable to relax normally after exercise.

It is common for leg blood flow and oxygen extraction and consumption to be measured by a catheter being inserted into an artery and vein. Instead, the group of researchers measured leg oxygen consumption using MRI technology to see if there were differences in the recovery period after exercise between the two groups.

Researchers found that there was in fact a difference, as leg blood flow and oxygen uptake recovery took longer in patients with dilated hearts.

“This could have important implications for exercise rehabilitation for heart failure patients,” said Haykowsky in a statement. “If we’re able to differentiate between these heart failure groups then in the future we could target therapies aimed at increasing blood flow to their muscles and improve their exercise capacity. Fatigue and exercise intolerance are Cardinal features in heart failure.”