MRI May Identify Those At High Risk For Heart Attacks, Strokes

November 12, 1996

A rapid nuclear magnetic resonance imaging (MRI) test can measure heart cell damage from heart attacks in living animals, according to studies at Johns Hopkins and Northwestern University.

The results put researchers another step closer to developing the technique for use in people to improve diagnosis and treatment of heart attacks, say the researchers. The study, which was supported by the National Institutes of Health, will be presented at 10:30 a.m., Nov. 13 at the American Heart Association's 69th annual Scientific Sessions in New Orleans.

The new method, first shown to work on animal heart cells and now on beating animal hearts, quickly measures damage to the heart when blood flow stops and restarts as in a heart attack. The technique, which reduces MRI times from four hours to seven minutes, produces sodium "maps" of the heart, showing dead cells as brighter and living cells as darker. In a heart attack, sodium accumulates in dead heart cells. Unlike echocardiography and stress tests, which are indirect measurements, the new MRI method directly measures the extent of damage to heart cells.

"We're near to creating a technique to rapidly image the naturally occurring sodium nucleus in cardiac cells in humans," says Joao A. C. Lima, M.D., a study co-author and an assistant professor of medicine. "An important question is what parts of the heart are alive, damaged or dead after a heart attack, and this could be an excellent method to determine which areas are viable."

In a study last year using rabbit heart cells, Hopkins scientists developed the rapid MRI method to detect the high sodium concentrations that accumulate in heart cells killed when blood flow stops and restarts, thus measuring how much heart tissue had died.

Results of the new study, using rabbits and dogs, show the technique also works in live small and large animals before and during blockage of blood flow in coronary arteries and after blood flow restarts. This information can be used to assess quickly a heart attack's damage and guide drug and surgical treatment such as angioplasty, the researchers say.

"This technique may help explain not only the anatomy of the dead tissue but also how well the cell membrane is functioning," says Lima.

Results of the sodium MRI study were confirmed in another Hopkins and Northwestern animal study using standard contrast-enhanced MRI, which generates maps of heart tissue based on hydrogen atoms.

The studies' other authors were Raymond J. Kim, M.D., and Enn-Ling Chen, M.D., of Hopkins and Robert M. Judd, M.D., and Francis J. Klocke, M.D., of Northwestern.


Johns Hopkins Medicine

Related Heart Attack Articles from Brightsurf:

Top Science Tip Sheet on heart failure, heart muscle cells, heart attack and atrial fibrillation results
Newly discovered pathway may have potential for treating heart failure - New research model helps predict heart muscle cells' impact on heart function after injury - New mass spectrometry approach generates libraries of glycans in human heart tissue - Understanding heart damage after heart attack and treatment may provide clues for prevention - Understanding atrial fibrillation's effects on heart cells may help find treatments - New research may lead to therapy for heart failure caused by ICI cancer medication

Molecular imaging identifies link between heart and kidney inflammation after heart attack
Whole body positron emission tomography (PET) has, for the first time, illustrated the existence of inter-organ communication between the heart and kidneys via the immune system following acute myocardial infarction.

Muscle protein abundant in the heart plays key role in blood clotting during heart attack
A prevalent heart protein known as cardiac myosin, which is released into the body when a person suffers a heart attack, can cause blood to thicken or clot--worsening damage to heart tissue, a new study shows.

New target identified for repairing the heart after heart attack
An immune cell is shown for the first time to be involved in creating the scar that repairs the heart after damage.

Heart cells respond to heart attack and increase the chance of survival
The heart of humans and mice does not completely recover after a heart attack.

A simple method to improve heart-attack repair using stem cell-derived heart muscle cells
The heart cannot regenerate muscle after a heart attack, and this can lead to lethal heart failure.

Mount Sinai discovers placental stem cells that can regenerate heart after heart attack
Study identifies new stem cell type that can significantly improve cardiac function.

Fixing a broken heart: Exploring new ways to heal damage after a heart attack
The days immediately following a heart attack are critical for survivors' longevity and long-term healing of tissue.

Heart patch could limit muscle damage in heart attack aftermath
Guided by computer simulations, an international team of researchers has developed an adhesive patch that can provide support for damaged heart tissue, potentially reducing the stretching of heart muscle that's common after a heart attack.

How the heart sends an SOS signal to bone marrow cells after a heart attack
Exosomes are key to the SOS signal that the heart muscle sends out after a heart attack.

Read More: Heart Attack News and Heart Attack Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to