Unfortunately, the silzone coated valves evidenced a much higher risk of infection than those without the coating. Endocarditis can lead to heart failure and be fatal without proper treatment. The heart's pumping action depends on the functioning of the heart valves. There is a one-way valve at the exit of each of the four chambers. The closing of these valves is responsible for the sounds made by the beating heart.
Papillary muscles help hold the valves in place.
Often the valves will last a lifetime, but they may also become damaged. Regurgitant valves allow some blood to flow backwards into the heart. Stenotic valves hinder the forward flow of blood. Endocarditis infections and rheumatic fever are the most common cause of damage to the heart. If a heart valve is sufficiently damaged it may be replaced by an artificial valve.