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Heart Valve replacement is a surgery procedure in which a one or more of the patient's heart valve is replaced by a different valve. The valves control the direction of blood flow through your heart. The opening and closing of the heart valves produce the sound of heartbeat.
There are four valves in a human heart:
- Aortic valve
- Mitral valve
- Tricuspid valve
- Pulmonary valve
Causes
The heart valve can be affected by a range of diseases; the valve can either become leaky or partially blocked. Heart valve surgery may be recommended if there is a narrowing of the heart valve (stenosis) or leaking of the heart valve (regurgitation).
These problems could be because of birth defects, Congenital, which most often affects the Aortic or Pulmonic valve. Valves may be the wrong size, have malformed leaflets, or have leaflets that are not attached to the annulus correctly.
Bicuspid aortic valve disease is a congenital valve disease that affects the aortic valve. Instead of the normal three leaflets or cusps, the bicuspid aortic valve has only two. Without the third leaflet, the valve may be stiff (unable to open or close properly) or leaky (not able close tightly). 
The structure or your valve can change due to a variety of diseases or infections, including rheumatic fever which is caused by an untreated bacterial infection or Endocarditis when germs, especially bacteria, enter the bloodstream and attack the heart valves, causing growths and holes in the valves and scarring.
Symptoms
- Shortness of breath and/or difficulty catching your breath. You may notice this most when you are active (doing your normal daily activities) or when you lie down flat in bed. You may need to sleep propped up on a few pillows to breathe easier
- Weakness or dizziness. You may feel too weak to carry out your normal daily activities. Dizziness can also occur, and in some cases, passing out may be a symptom
- Discomfort in your chest. You may feel a pressure or weight in your chest with activity or when going out in cold air
- Palpitations. This may feel like a rapid heart rhythm, irregular heartbeat, skipped beats or a flip-flop feeling in your chest
- Swelling of your ankles, feet or abdomen. This is called edema. Swelling may occur in your belly, which may cause you to feel bloated
- Rapid weight gain. A weight gain of two or three pounds in one day is possible
There are two types of valves that are used namely Mechanical valves and Tissue valves
Diagnosis
The following tests may be used to conclude and diagnose valve diseases
* Echocardiography
* Transesophageal echocardiography
* Cardiac catheterization (also called an angiogram)
* Radionuclide scans
* Magnetic resonance imaging (MRI)
During a physical examination the doctor will listen to your heart to hear the sounds the heart makes as the valves open and close. A murmur is a swishing sound made by blood flowing through a stenotic or leaky valve.
There are different types of valves that can be used
Mechanical valves
Mechanical valves are designed to outlast the patient, and have typically been stress-tested to last several hundred years. Although mechanical valves are long-lasting and generally only one surgery is needed, there is an increased risk of blood clots forming with mechanical valves. As a result, mechanical valve recipients must generally take anti-coagulant drugs such as Warfarin for the rest of their lives, which makes the patient more prone to bleeding.
Tissue valves
Tissue heart valves are usually made from animal tissues, either animal heart valve tissue or animal pericardial tissue. The tissue is treated to prevent rejection and calcification.
There are alternatives to animal tissue valves. In some cases a homograft - a human aortic valve - can be implanted. Homograft valves are donated by patients and harvested after the patient dies. The durability of homograft valves is probably the same for porcine tissue valves. Another procedure for aortic valve replacement is the Ross procedure. In a Ross procedure, the aortic valve is removed and replaced with the patient's own pulmonary valve. A pulmonary homograft (pulmonary valve taken from a cadaver)is then used to replace the patient's own pulmonary valve. This procedure was first used in 1967 and is used primarily in children
Homograft
A homograft or allograft is a human valve obtained from a donor. This type of valve is particularly beneficial for pregnant women and children, because it does not require long-term anticoagulation therapy. In addition, it can provide excellent hemodynamic performance, allowing for natural function of the surrounding structures. Because the availability of these valves depends on donors, supply is limited.
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