A new study into the causes of leakage in one of the heart's most complex valve structures could lead to improved diagnosis and treatment of the condition.
An estimated 1.6 million Americans suffer moderate to severe leakage through their tricuspid valve, a complex structure that closes off the heart's right ventricle from the right atrium. Most people have at least some leakage in the valve, but what causes the problem is not well understood.
A new study, published online in the journal Circulation
on August 1, 2011, found that either dilating the tricuspid valve opening or displacing the papillary muscles that control its operation can cause the valve to leak. A combination of the two actions can increase the severity of the leakage, which is called tricuspid regurgitation.
"We think this is the first in vitro investigation into the mechanics of the tricuspid valve, and that our findings into the mechanisms that cause tricuspid regurgitation could lead to improved diagnosis and treatment," said Ajit Yoganathan, Regents professor and Wallace H. Coulter Distinguished Faculty Chair in Biomedical Engineering in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
The tricuspid valve consists of three flaps that open to allow blood to flow from the heart's upper right chamber to the ventricle. To close the valve, the flaps re-cover the opening, keeping blood from flowing back into the chamber it just left. When the valve is leaky or doesn't close tightly enough, blood flows backward into the chamber just after the heart contracts.
Tricuspid regurgitation has been increasingly recognized as a source of disease in patients with chronic mitral valve regurgitation, but surgical repair of the tricuspid valve alone is recommended only in rare cases. If an individual suffers from severe tricuspid regurgitation, surgeons will sometimes repair the tricuspid valve during a surgery to repair other leaky heart valves.