Additional Damage From Heart Attack Occurs Within 48 Hours Of Recovery

October 21, 1998

The tiniest blood vessels nourishing the heart are at risk of damage not only during a heart attack but also after normal blood flow returns through the region, a Johns Hopkins-led animal study has found.

The study used magnetic resonance imaging (MRI) for the first time to measure the extent and time course of capillary blockage following simulated heart attacks in laboratory animals. Researchers found that the obstruction is uneven in these vessels and increases up to threefold during the 48 hours following return of blood flow. The consequences can affect nearly 10 percent of the left ventricle -- the heart's main pumping chamber.

Results of the study, supported by the American Heart Association and the National Heart, Lung and Blood Institute, were published in the Sept. 8 issue of Circulation: Journal of the American Heart Association.

During a heart attack, dying blood cells and debris can clog the heart's capillaries -- the body's narrowest blood vessels. If the vessels stay clogged for a long time, the capillaries remain blocked, preventing return of normal blood flow even after the body recovers from a heart attack. This can put a patient at risk for later complications, such as another heart attack, congestive heart failure or stroke.

In treating heart attack patients, physicians try to reperfuse -- or return blood flow -- to the area using drugs, angioplasty or surgery.

"But reperfusion is not uniform," says Carlos E. Rochitte, M.D., lead author of the study and a postdoctoral cardiology fellow at Hopkins. "The core area affected by the attack may be damaged so badly that the capillaries remain blocked."

Identifying the extent of obstruction early could aid in the development of new medications to open up the blocked vessels, according to Jo o A.C. Lima, M.D., and David A. Bluemke, M.D., Ph.D., senior authors of the study.

Researchers studied vascular obstruction in animal models by blocking the coronary arteries for 90 minutes to simulate a heart attack. Then they observed the region of the heart attack two hours, six hours and 48 hours following return of blood flow. At two hours, vascular obstruction affected an average of 3.2 percent of the left ventricle. At six hours, obstruction affected an average of 6.7 percent of the left ventricle; at 48 hours, the obstruction affected an average of 9.9 percent of the left ventricle.

Further study is necessary to determine why some people have more obstruction than others, Rochitte says.

The study's other authors were Scott B. Reeder, Ph.D.; Elliot R. McVeigh, Ph.D.; Toshiya Furuta, M.D.; and Lewis C. Becker, M.D., of Hopkins; and Jacques A. Melin, M.D., of the University of Louvain, Brussels, Belgium.

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