What is mitral valve prolapse?
Mitral valve prolapse (MVP) is a heart valve disorder and malfunction. One of the most common heart valve conditions, it takes place when the mitral valve doesn’t shut as completely or tightly as it should.
This is due to an irregular ballooning movement (prolapse) of one or more stiffened, elongated, or abnormal leaflets (flaps or cusps) into the left atrium when the heart contracts.
The condition is largely hereditary and manifests with a wide degree of severity. It can range from so mild that it goes totally unnoticed to severe enough that it is troublesomely symptomatic and potentially fatal, requiring surgery and/or other treatments. Specific measurements help to determine the extent of a prolapse. Myxomatous degeneration is a common cause of mitral valve prolapse.
In some people who have this disorder, which generally follows a benign course, blood leaks back into the left atrium from the left ventricle during prolapse. This is known as mitral regurgitation (MR). Regurgitation, particularly when it is severe, can place a lot of strain on the heart, causing problematic symptoms and complications. On rare occasions, MR can cause death.
How do the heart valves and chambers work?
The heart contains four chambers and four valves. Together, they regulate blood flow into and out of the vital organ, ensuring proper function and keeping us alive.
Two atrioventricular valves (the tricuspid valve and the mitral valve) control the flow of blood into the heart. Two semilunar valves (the pulmonary valve and the aortic valve) control the flow out. Each one is located at the exit of a specific chamber, opening and closing when the heart contracts (systole and diastole).
The bicuspid valve is found at the exit of the left atrium. The tricuspid valve is found at the exit of the right atrium. The aortic valve is found at the left ventricle exit. The pulmonary valve is found at the right ventricle exit. All four of the valves operate in one direction only, opening to allow blood to flow forward and closing to prevent it from flowing back.
Note: The mitral valve is also known as the bicuspid valve because it contains two cusps. The closed leaflets resemble a bishop’s mitre, a type of traditional ceremonial hat, which is where the valve gets its name. The bicuspid name references the two valvular flaps.
How does a normal mitral valve function?
The bicuspid operates between the left atrium and left ventricle. Freshly oxygenated blood from the pulmonary veins fills the atrium, causing it to contract. This pressure pushes open the mitral valve, allowing blood to pass into the ventricle. When the ventricle contracts, its pressure forces the valve shut, creating a tight, trapdoor-like seal and preventing blood from flowing back into the left atrial chamber.
What goes wrong in people with mitral valve prolapse?
In people with MVP, the leaflets of the bicuspid valve close unevenly, causing a slight bulge or flop when the left ventricle constricts. The mitral leaflets may be enlarged, thickened, or damaged, or they may be misaligned in some cases. A prolapsed valve may continue to seal normally and allow blood to flow in one direction. However, problems can arise if it doesn’t shut totally and allows blood to leak back. While the leakage is often minor in those with regurgitation, treatment is necessary when it is significant.