MITRAL VALVE PROLAPSE
The most common heart valve abnormality is called mitral valve
prolapse (MVP), which affects mostly women between the ages of 20 and 40.
It can go undetected for years, as symptoms usually do not occur until adolescence
or even adulthood. It is a condition of the mitral valve, a two-flapped heart
valve between the left atrium and left ventricle. In MVP, one or both of the
valve flaps are too large, and the mitral valve does not close evenly with
each heartbeat. Because of this imperfect closing, the valve itself slightly
balloons back into the left atrium, sometimes causing what is known as a "click".
With the flap there may sometimes be a slight backward leaking of blood (regurgitation)
as well, resulting in a heart murmur.
It seems that MVP is an inherited disorder, although the exact
genes are not known. If proper precautions are taken it will not affect life
expectancy, and generally has no impact on normal activities.
What are the symptoms?
Generally, a stressful situation (childbirth, change in job situation
or marital status, viral illness) brings on symptoms that ordinarily would
not be present. Some 60% of those with MVP never show symptoms. Some symptoms
include:
- Irregular heartbeat or palpitations, particularly when lying on the left
side
- Non-specific sharp or dull chest pain lasting from a few seconds to several
hours, occurring at rest rather than during exertion
- Panic attack, a sudden feeling of anxiety or doom for no apparent reason
- Fatigue and weakness, even after slight exertion; sometimes misdiagnosed
as Chronic Fatigue Syndrome or depression
- Tachycardia, increased heartbeats often after exertion
- Migraine headaches, resulting from abnormal nervous system control of blood
flow
The condition can be detected during a routine check-up with a simple stethoscope.
After the ventricle begins to contract, a clicking sound can be heard, the sound
of the abnormal valve fighting the pressure of the left ventricle. The diagnosis
can be confirmed with a cardiac echo or echocardiogram, which can also determine
the level of severity of the prolapse and the degree of regurgitation. Most
patients can be monitored simply, with a follow-up checkup every few years.
Common risks and problems associated with MVP
Many MVP patients never experience any symptoms. However, rare complications
include chest pain and irregular heart beat, both of which can be treated with
medication, usually a beta-blocker. Another rare complication involves formation
of blood clots on the valve, making an MVP patient vulnerable to strokes; this
problem requires treatment with medication.
The most common and serious MVP-related problem, endocarditis, involves bacterial
infection of the mitral valve. Although it can be fatal if left untreated, endocarditis
can be easily prevented. MVP patients are most commonly vulnerable to introduction
of bacteria into the bloodstream when they are undergoing certain medical procedures,
particularly dental work or minor surgery. To avoid this, patients should inform
their doctor or dentist that they have MVP, and be given preventative treatment
before the procedure.
When is surgery recommended?
Although most MVP patients do very well with treatments and preventive measures,
there is sometimes need for heart surgery to either repair or replace the mitral
valve. This occurs only among patients who experience severe mitral regurgitation,
which can result in progressive heart enlargement, and ultimately, heart failure.
Surgeons are more likely to perform corrective surgery rather than replace the
valve with an artificial one, mainly because the introduction of an artificial
valve requires lifelong use of blood thinners to prevent clotting.
MITRAL STENOSIS
Mitral Stenosis is a heart valve disorder characterized by narrowing or obstruction
of the mitral valve, which prevents the valve from opening properly. Also known
as Mitral valve obstruction, it affects about 2 out of 10,000 people. Symptoms
usually develop between the ages of 20 and 50.
Causes & Risk Factors
Mitral Stenosis most commonly occurs in people who have had rheumatic fever
but can be caused by any disorder that causes narrowing of the mitral valve.
Congenital mitral stenosis alone is rare. It more commonly occurs with complex
groups of cardiac abnormalities.
Narrowing of the mitral valve obstructs blood flow from the left atrium to
the left ventricle. This can reduce the amount of blood that flows forward to
the body. The atrium enlarges as pressure builds up in it, and blood may backflow
into the lungs resulting in fluid in the lung tissue.
Symptoms may begin with an episode of atrial fibrillation, or may be triggered
by pregnancy or other stress on the body such as respiratory infection, stroke,
endocarditis and other cardiac disorders.
Prevention
Mitral stenosis cannot be prevented but complications can be. As with mitral
valve prolapse, advise your physician or dentist of any history of heart valve
disease before receiving treatment to prevent a bacterial infection.
Symptoms
There are often no symptoms, or symptoms may appear or worsen with exercise
or increase in heart rate. Symptoms include:
- difficulty breathing after exercise or when lying flat, also awakening at
night with difficulty breathing
- cough (may have blood in the sputum)
- fatigue, tired easily
- frequent respiratory infections such as bronchitis
- chest discomfort
- tight, crushing, pressure, squeezing, constricting
- radiates to the arm, neck, jaw, or other areas
- increases with activity, decreases with rest
- sensation of feeling the heart beat
- swelling of feet or ankles
Signs and tests
A stethoscope examination reveals a distinctive murmur, snap, or other abnormal
sounds. This means a rumbling sound is heard over the point of the heart during
the resting phase of the heartbeat, and it gets more pronounced just before
the heart contraction begins. Examination may also reveal irregular heartbeat
or lung congestion. Blood pressure is usually normal. There may be vibration
or a tapping on palpation over the heart making it difficult to distinguish
from a heart tumor.
Narrowing or obstruction of the valve, or enlargement of the atrium may show
on an echocardiogram, Doppler ultrasound, chest X-ray, ECG or coronary angiography.
Treatment
No treatment may be necessary if symptoms are absent or mild. Hospitalization
may be required for diagnosis and for treatment of more severe symptoms. Medications
include diuretics, digoxin, or antiarrhythmics. Anticoagulants may be used to
prevent blood clots. Heart valve surgery or replacement of the valve may be
necessary. Balloon valvuloplasty may be considered instead of surgery.
Expectations
The disorder may be mild or without symptoms. It may be more severe and eventually
disabling. Complications may be severe or life threatening. Mitral stenosis
is usually controllable with treatment, and improved with surgery.
Complications
- enlargement of the atrium
- incomplete atrial emptying
- heart failure
- pulmonary edema
- atrial fibrillation
- stroke
- emboli to the intestines, lungs, or other areas
MITRAL REGURGITATION
Mitral Regurgitation is a disorder in which the mitral heart valve does not
close properly, causing blood to leak into the left atrium when the left ventricle
contracts. Mitral regurgitation affects approximately 5 out of 10,000 people.
Causes and risk factors
Regurgitation is caused by disorders that weaken or damages the valve. Inadequate
closure of the mitral valve causes blood to backflow to the left atrium decreasing
the blood flow to the rest of the body causing the heart to pump harder to try
to compensate for the decreased blood flow. It may also be the result of dysfunction
or injury to the valve following MI or infective endocarditis, which may result
in rupture of the valve, papillary muscle, or chordae tendineae (the structures
that anchor the valve cusps). Such a rupture results in the valve leaflet protruding
into the atrium, leaving an opening for the backflow of blood.
Risk factors include an individual or family history of the above disorders.
Prevention
Prompt treatment of causative disorders reduces the risk of mitral regurgitation.
As with mitral stenosis and mitral valve prolapse, you should advise your physician
or dentist of any history of heart valve disease before receiving treatment
to prevent a bacterial infection.
Symptoms
There may be an abrupt onset of symptoms.
- shortness of breath
- rapid respirations
- sensation of feeling the heart beat
- chest pain unrelated to coronary artery disease or myocardial infarction
- cough
Signs and tests
Palpation may show a vibration over the heart. A stethoscope may reveal a distinctive
murmur in the heart. If fluid backs up into the lungs, there may be signs of
congestion of the pulmonary (lung) veins. Blood pressure is usually normal.
Billowing of the mitral valve and/or regurgitation of blood may show on an echocardiogram
or a coronary angiography.
A chest X-ray may also show fluid in the lungs or prominent pulmonary veins.
Swan-Ganz left heart catheterization pressure readings will record a marked
elevation of left atrial pressure. An ECG usually shows a normal sinus rhythm,
but may show arrhythmias such as atrial fibrillation. Other tests may include
a chest MRI scan, radionucleotide scans, or a CT scan of the chest.
Treatment
Hospitalization may be required for diagnosis and treatment of severe symptoms.
Emergency surgery is often necessary if acute regurgitation is a result of endocarditis,
MI, or ruptured cordae.
Antibiotics may be prescribed if there is a bacterial infection. Antiarrhythmics
may be needed to control irregular rhythms. Vasodilators reduce the workload
of the heart. Digitalis may be used to strengthen heartbeat, and diuretics to
remove excess fluid such as fluid in the lungs. Anticoagulants or antiplatelet
medications may be used to prevent clot formation if atrial fibrillation is
present. When blood pressure cannot be maintained, in emergency situations,
the intra-aortic balloon pump (IABP) reduces backflow by lowering resistance
in the aorta.
Expectations
The outcome varies and depends on the severity of the acute regurgitation.
It can sometimes be controlled with medications, but surgery is often necessary
as it may become a chronic condition.
Complications
- chronic mitral regurgitation
- endocarditis
- heart failure
- pulmonary emboli
- stroke
- clots of other areas
- arrhythmias, including atrial fibrillation and lethal
