Research finds heart remodeling rapidly follows cardiac injury

September 4, 2012

Cardiac injury leads to significant structural changes in the heart, including enlargement, excess formation of fibrous growth tissue, and abnormalities of the coronary vasculature. While associated factors have been targeted for therapeutic intervention, the results have been conflicting. Most studies have investigated these changes after six days of injury. However, advanced stages of remodeling have already begun by day seven following injury. New research reveals that morphological changes in response to cardiac injury occur rapidly, with implications for the development of therapeutic strategies. The results are published in the October issue of The American Journal of Pathology.

"We analyzed and have demonstrated for the first time the early interaction and coordination of morphological changes, cell populations, and following pathological cardiac insult," reports lead investigator Troy A. Baudino, PhD, of the Cardiovascular Research Institute at Texas A&M Health Science Center, Temple, TX. "The time course of our study allows these events to be correlated to one another, providing valuable insight for future studies of cardiac pathology."

The investigators induced heart injury in mice through transverse aortic constriction (TAC). A control group of mice underwent a surgical procedure without the aortic constriction, for comparison. They evaluated acute cardiac modeling events beginning two days after surgery, including changes in hypertrophy, collagen deposition, capillary density, and .

Within 48 hours after injury, the left ventricular free wall and septum were significantly enlarged, with an increase in heart weight and relative wall thickness compared to controls. In addition to this hypertrophy, a significant decrease in capillary density was observed two days after TAC. Increased levels of pericytes, which are connective tissue cells in small blood vessels, were associated with the reduction in capillary density, supporting earlier research that suggested a role for pericytes in stabilizing vessels and minimizing vascular . "The participation of pericytes could mark the period where degradation transitions to new capillary formation and re-vascularization," says Dr. Baudino.

Investigators observed increased fibroblasts and collagen seven days following TAC, contributing to the increased heart weight between two and seven days after injury. "We found that these changes take place concurrently with vascular re-growth," says Dr. Baudino. "It is possible that while the expanding fibroblast population is depositing excess extracellular material, a process that stiffens the heart, it also simultaneously stimulates capillary growth, to deliver more oxygen and nutrients to the expanding myocardium. Given this implication, regulation of fibroblasts may offer an advantageous route of therapy."

Dr. Baudino notes that the human response to pressure overload such as hypertension is more gradual than in the TAC mouse model and may vary with respect to the specific timing of remodeling. "Future studies should examine the remodeling events in a clinical setting. However, our results provide a basis for investigating how these events are coordinated during remodeling and the importance of possible intervention before pathological remodeling appears," he concludes.

Explore further: Mural cells from saphenous vein could have long-term benefits in heart attacks

More information: "Pressure Overload Induces Early Morphological Changes in the Heart," by Colby Amsden Souders, Thomas Keith Borg, Indroneal Banerjee, and Troy Anthony Baudino (dx.doi.org/10.1016/j.ajpath.2012.06.015). It appears in The American Journal of Pathology, Volume 181, Issue 4 (October 2012)

Related Stories

Mural cells from saphenous vein could have long-term benefits in heart attacks

August 25, 2011
Stem cell therapies promise to regenerate the infarcted heart through the replacement of dead cardiac cells and stimulation of the growth of new vessels. New research has found the transplantation of stem cells that reside ...

ESC calls for renaming of term cardiac hypertrophy

June 27, 2011
Sophia Antipolis, France: 27 June 2011: The European Society of Cardiology (ESC) Working Group on Myocardial Function is calling for a redefinition of the term cardiac hypertrophy which is currently used to describe changes ...

Recommended for you

Could this protein protect people against coronary artery disease?

November 17, 2017
The buildup of plaque in the heart's arteries is an unfortunate part of aging. But by studying the genetic makeup of people who maintain clear arteries into old age, researchers led by UNC's Jonathan Schisler, PhD, have identified ...

New model estimates odds of events that trigger sudden cardiac death

November 16, 2017
A new computational model of heart tissue allows researchers to estimate the probability of rare heartbeat irregularities that can cause sudden cardiac death. The model, developed by Mark Walker and colleagues from Johns ...

Popular e-cigarette liquid flavorings may change, damage heart muscle cells

November 16, 2017
Chemicals used to make some popular e-cigarette liquid flavorings—including cinnamon, clove, citrus and floral—may cause changes or damage to heart muscle cells, new research indicates.

Possible use for botulinum toxin to treat atrial fibrillation

November 16, 2017
From temporarily softening wrinkles to easing migraines, botulinum toxin has become a versatile medical remedy because of its ability to block nerve signals that can become bothersome or risky.

Proteome of the human heart mapped for the first time

November 15, 2017
A healthy heart beats about two billion times during a lifetime, thanks to the interplay of more than 10,000 proteins. Researchers from the Max Planck Institute of Biochemistry (MPIB) and the German Heart Centre at the Technical ...

First transcatheter implant for diastolic heart failure successful

November 15, 2017
Results presented today at the American Heart Association Scientific Sessions and published in Circulation show that a new device designed to treat diastolic heart failure is safe and effective. The first patient in the randomized, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.