Mitral valve prolapse is a disease that affects the mitral valve of the heart. In it’s normal operation the mitral valve controls the flow of blood between the two left chambers of the heart viz. the left atria and the left ventricle and it prevents any backflow of blood. Sometimes the valve doesn’t function properly. The flaps of the valve known as the cusps become floppy and do not close tightly. This condition is known as Mitral Valve Prolapse.
In Mitral Valve Prolapse, the valve doesn’t close properly and blood flows into the atrium. When the left ventricle contracts one or both of the cusps of the mitral valve flop or bulges back into the left atrium. This bulging back action is referred to as a prolapse and it prevents the valve from forming a tight seal. As a result of this the blood flows backward from the left ventricle into the left atrium. Backward flow occurs only in some cases and in most cases of Mitral Valve Prolapse the patients do not have any back flow nor any serious symptoms or complications because even though the valve prolapsed it can still form a tight seal.
In case when the back flow does indeed occur it leads to complications like arrhythmias i.e. irregular heartbeat, shortness of breath and chest pain. If the condition persists it can grow worse over an extended time period. It leads to changes in the heart’s size and causes a build up of pressure in the left atrium and lungs. There is also an elevated risk of heart valve infections due to back flow.
Mitral Valve Prolapse is also known by a variety of other names such as Barlow’s Syndrome, Floppy valve syndrome, myxomatous mitral valve, click-murmur syndrome etc. It is called click-murmur syndrome because of the characteristic clicking sound of the cusps prolapsing into the atrium and an adjoining murmur is heard. The exact aetiology of Mitral valve Prolapse is unknown. In most of the cases the patients are born with it. The disorder tends to be inherited in families and shows an increasing connection with people who were born with connective tissue disorders, Marfan syndrome for instance.
There are two known structural defects of the cusps that lead to Mitral Valve Prolapse. The flaps may either be oversized and thickened or they may be floppy. The supporting tissues of the flaps become too stretchy and they bulge into the atrium. In some patients both these defects are found but either way it prevents the valve from making a tight seal. Mitral Valve Prolapse is known to occur in people of all age groups irrespective of sex. MVP with severe complications is more often seen in men older than 50. Certain factors raise the risk for Mitral Valve Prolapse which includes:
- Connective Tissue Disorders
- Skeletal Problems
- Some types of Muscular Dystrophy i.e. a hereditary disease of the muscular system
In most cases there are no marked symptoms as there is no backflow. In case of backflow the symptoms include:
- Palpitations or rapid heartbeats
- Shortness of breath
- Chest Discomfort
The symptoms vary from person to person and can lead to further complications in the long run. These complications are rare and are most often caused by back flow of blood. Back flow causes blood to flow from the left ventricle into the left atrium and it may even continue all the way back to the lungs, leading to shortness of breath.
This back flow puts strain on the muscles of the ventricle and the atrium and if it continues over a long period of time it may lead to arrhythmias or abnormal rate of muscle contractions in the heart causing abnormal heartbeat. Another complication is that the deformed flaps are an ideal substrate for bacteria that may be in the bloodstream. These bacteria attach to the valve and cause serious infections called Infective Endocarditis. Mitral Valve Prolapse is the most common disorder that puts patients at risk of Infective Endocarditis.
Mitral Valve Prolapse is usually diagnosed by the doctor by conducting a physical examination and listening to the heartbeat. The doctor listens for any characteristic click and murmur sounds. After the physical examination the patient is made to undergo various tests to confirm the condition.
The following testing procedures are employed:
- Echocardiography, this technology uses sound waves to create a picture of the patients heart.
- Doppler Ultrasound test. This test helps monitor the speed and direction of blood flow through the mitral valve
- Chest X ray to check for fluid in the lungs or an enlargement in the heart.
Most patients do not have any serious symptoms or severe complications and are hence not in need of any major treatment procedures. But in case of serious complications treatment is essential for relieving the symptoms, preventing infective endocarditis etc. Medicines are used to relieve a host of symptoms like beta blockers for palpitations and vasodilators to widen the blood vessels. In addition to this there are various surgical methods of treatment like mitral Valve Replacement and mitral valve repair. Valve repair is preferred over replacement as it is less likely to weaken the heart and it reduces the risk of infections and eliminates lifelong use of blood thinning medicines.