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A heart valve is a biological one-way valve that allows blood to flow in one direction through the chambers of the heart.A mammalian heart usually has four valves. Together, the valves determine the direction of blood flow through the heart.
Attempts to improve the design of the valve and speed manufacturing, however, led to a weaker structure, with serious consequences. Beginning in 1979, Björk–Shiley valves with the convexo-concave design had a tendency to develop fractures in the outflow strut which could result in catastrophic valve failure and possibly sudden cardiac death.
An artificial heart valve is a one-way valve implanted into a person's heart to replace a heart valve that is not functioning properly (valvular heart disease).Artificial heart valves can be separated into three broad classes: mechanical heart valves, bioprosthetic tissue valves and engineered tissue valves.
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta.It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve.
The metric equivalent flow factor (K v) is calculated using metric units: =, where [3]. K v is the flow factor (expressed in m 3 /h), Q is the flowrate (expressed in m 3 /h), SG is the specific gravity of the fluid (for water = 1),
The first heart sound, or S 1, forms the "lub" of "lub-dub" and is composed of components M 1 (mitral valve closure) and T 1 (tricuspid valve closure). Normally M 1 precedes T 1 slightly.
Veins (/ v eɪ n /) are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart.Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart.
A medical monitoring device displaying a normal human heart rate. Heart rate is the frequency of the heartbeat measured by the number of contractions of the heart per minute (beats per minute, or bpm).