Study Of Heart Challenges Traditional Valve Theory
The concept of cardiac valves as passive, collagen-coated "tent flaps" is being challenged by Bethesda and Albuquerque investigators.Two of the heart's valves—the mitral and the tricuspid—appear to have functioning nerve, muscle, and blood vessel systems."These systems certainly are not the primary force in valve closure," stresses Theodore Cooper, MD, PhD. "But they may provide an additional factor to consider in understanding the total role of the heart."Anatomists have known for more than 100 years that muscle fibers are present in both human and animal cardiac valves. It has been nearly 50 years since German scientists spotted neural structures in them. But it remained for Dr. Cooper and colleagues to show that these systems were not vestigia of embryonic life or evolution.Investigations to date have been primarily with the septal leaflet of the mitral valve from dogs and cats.