page_title: Artificial heart valve
section_title: Tilting-disc valves
hierarchical_section_title: Artificial heart valve / Types of artificial heart valve / Mechanical valves / Types of mechanical valves / Tilting-disc valves
caption_attribution_description: English: Image of the Chitra valve
context_page_description: An artificial heart valve is a one-way valve implanted into the heart of a patient to replace a disfunctional native heart valve.
  The human heart contains four valves: tricuspid valve, pulmonic valve, mitral valve and aortic valve. Their main purpose is to keep blood flowing in one direction through the heart, and from the heart into the major blood vessels connected to it. Heart valves can malfunction for a variety of reasons, which can impede the flow of blood through the valve and/or let blood flow backwards through the valve. Both processes put strain on the heart and may lead to serious problems, including heart failure.
  Artificial heart valves can generally be separated into three classes: mechanical heart valve, bioprosthetic valve and tissue heart valve.
  Although some dysfunctional valves can be treated with drugs or repaired, others need to be replaced with an artificial valve. The main problem with artificial valves today is the regurgitation caused by form degeneration, and to repair the deformed valves, in most cases, support in the ventricle is required for any surgical operation to be performed.
context_section_description: Introduced in 1969, the first clinically available tilting-disc valve was the Bjork-Shiley valve. Tilting‑disc valves, a type of swing check valve, are made of a metal ring covered by an ePTFE fabric. The metal ring holds, by means of two metal supports, a disc that opens when the heart beats to let blood flow through, then closes again to prevent blood flowing backwards. The disc is usually made of an extremely hard carbon material (pyrolytic carbon), enabling the valve to function for years without wearing out.
caption: tilting-disc valve
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