We have specialized x-ray fluoroscopy machines and computer systems that allows us to use equipment that is normally used for cardiac catheterizations. By modifying the amount of x-ray and intensifying it, we can obtain a picture of the valve. Hershey researchers have done extensive work with BSCC valves for more than eight years, and Gilchrist says that this experience is why Hershey was chosen as the primary test site for patients in the United States, Canada and United Kingdom. The base of the valve is a metal ring with metal struts fused to it. These struts hold a single disk in place, allowing it to tilt between the open and closed position with the contraction of the heart.
Blood flows and is pushed from the left atrium through the open valve into the left ventricle.
At the beginning of the heart beat, the left ventricle starts its contraction, and the valve is closed by the blood in the ventricle. Historically this type of valve has been very reliable. However, modifications were made to the original disk to improve its performance and unfortunately, some models of the valve developed fractures of the struts over time, allowing the disc itself to break free from the valve structure. In the absence of the disk, blood can still flow freely from the left atrium to the left ventricle between the heart's contraction. However, without the valve to check blood flow during contractions, blood may flow from the ventricle back toward the atrium.