heart to function properly, the four heart chambers must beat in an
organized manner. Under normal conditions, the heart valves let blood
to flow in only one direction. Problems with a heart
valve (or valves) may occur because of disease, injury or congenital
factors. Two kinds of problems usually occur. If a valve is narrowed
(stenotic) the heart may have to work much harder to pump blood across
the valve. A second type of problem occurs when a valve (or valves)
does not close completely, causing some blood to be pumped backwards
(regurgitation / incompetence) instead of forwards
in the heart. Both types of problems can cause the heart to work too
hard and eventually weaken over time.
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to see how the heart and valves work.
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are heart valves?
valves are thin flexible flaps of connective tissue. The four heart
tricuspid valve, located between the right atrium and right ventricle;
pulmonary or pulmonic valve, between the right ventricle and the pulmonary
mitral valve, between the left atrium and left ventricle; and
aortic valve, between the left ventricle and the aorta.
occurs only when there's a difference in pressure across the valves
that causes them to open.
valve has a set of flaps (also called leaflets or cusps). The mitral
valve has two leaflets while the other valves have three. The mitral
and tricuspid valves are connected to small muscles (papillary) along
the wall of the heart by small string like tendons (chordeae tendineae).
Papillary muscle contraction opens these valves. The aortic and pulmonic
valves are differently shaped do not have cordae tendineae nor papillary
problems may be caused by infection, heart disease, trauma or congenital
valvular conditions and may be isolated to a single valve or effect
multiple valves. Right sided (tricuspid, pulmonary) valvular disease
is much less common than left sided (aortic, mitral) valvular disease.
Roughly 90% of valvular disease is chronic, having developed gradually
over many years. Complications of rheumatic fever, congenital disorders
and aging cause the vast majority of chronic valvular disease. The
remaining 10% of valvular disease that develops acutely (over days
to weeks) is often due to complications of recent heart attack or
fever- Most valvular heart disease is still caused by childhood
rheumatic fever (a complication of untreated streptococcal infection).
During a streptococcal infection (typically in the throat) the body
makes its' own antibodies to fight the bacterial infection. Antibodies
recognize the structure of certain parts of the bacterial surface,
attach to it and destroy it. Unfortunately, the surface structure
of certain body tissues (heart valves, skin, joints, kidneys, etc..)
may resemble that on certain types of streptococcal bacteria. With
rheumatic fever antibodies that normally fight infection may attack
the body's own tissues. It is important to stress that it is not
bacteria that directly cause injury.
fever usually occurs 2-6 weeks after untreated strep throat. Symptoms
of rheumatic fever are multiple and may include:
(pain, swelling and warmth) that shifts from joint to joint. Larger
joints such as hips and knees tend to be more frequently effected.
failure, new heart murmurs, fast heart rate
or pericardial friction rub due to inflammation
of heart muscle, valves or pericardium. This
is called carditis and occurs during rheumatic fever. Carditis is
different from delayed valvular disease that slowly develops over
many years after rheumatic fever has occurred. The latter is due
to slow but progressive thickening of effected heart valves initially
injured during rheumatic fever..
may form under the skin on the backs side of the wrist, elbow, and
temporary skin rash lasting several days may occur.
to brain tissues may cause repetitive involuntary writhing movement
of the head and arms. This is called chorea.
of rheumatic fever in the USA has decreased greatly in recent years
due to the use of antibiotics to treat strep throat. Delayed symptoms
of heart valve disease may take 10-20 years to appear and gradually
worsen over time. Rheumatic fever may effect a single or multiple
valves. Symptoms that occur years later is usually from injury to
the mitral and aortic valves.
Endocarditis is infection of heart valves directly with bacteria
or fungi. Infection may occur after certain dental /surgical procedures
or with IV drug use. Infective endocarditis can involve any heart valve
but most commonly involves the aortic or mitral valve (left sided heart
disease). Infection of only the tricuspid valve (right sided disease)
is usually seen in IV drug users.
dental or surgical procedures a small amount of bacteria may get into
the blood stream. This is almost never a problem for otherwise healthy
persons with normal heart valves- the body easily takes care of this
on its own. Bacteria from these procedures can infect previously
injured heart valves (usually from rheumatic fever). Therefore, a
dose of an antibiotic (prophylactic=preventative) is always recommended
prior to dental work and certain types of surgery for people with
heart valve disorders to prevent endocarditis.
(a mixture of bacteria and blood clots) may form on valves of the
left, right or both sides of the heart. Vegetations can embolize (break
loose) and travel to other parts of the body. Emboli from the left
heart valves (mitral or aortic) will travel via the aorta to the body;
those from the right heart valves (tricuspid or pulmonic) will travel
to the lungs. Emboli lodging in the brain can cause a stroke. Emboli
may carry infection to other parts of the body. Emboli lodging in
the lungs may cause shortness of breath and cough.
is divided into several categories
endocarditis usually occurs on previously normal valves and
is most often due to IV drug use and is due to aggressive types
of bacteria associated with contaminated needles. Rapid destruction
of the heart valve(s) can happen, causing severe heart
of acute infective endocarditis may include:
of breath and chest pain.
are usually quite ill. Heart murmurs may be heard
as well. Stroke symptoms may occur if vegetations break loose and
lodge in brain arteries. Severe heart failure may occur if the aortic
or mitral valves rupture.
endocarditis usually occurs on artificial or previously injured
valves and progresses more slowly. Bacteria associated with subacte
endocarditis are not as virulent as bacteria
associated with acute endocarditis. Symptoms of subacute infective
endocarditis,often not as obvious, may include:
very run down
often think they have recurrent flu or may have been treated with
antibiotics several times with antibiotics for presumed bacterial
infections such as bronchitis.
in the case of acute infective endocarditis bacterial vegetations
can break loose and go to other parts of the body. Physical signs
are related to the part of the body they lodge in:
hemorrhages may be seen in finger and toe nail beds;
hemorrhages may be seen in the eyes;
nodules (Osler nodes) may be felt on finger and toe tips;
plaques (Janeway lesions) may occur on the palms of the hands and
soles of the feet.
of infective endocarditis is made if blood cultures are positive for
bacteria or fungi known to cause endocarditis and there is evidence
of valvular injury or vegetations. The heart and valves are imaged
generally requires hospitalization and intravenous antibiotic therapy
for at least 4 weeks. Infection is almost never adequately treated
with oral antibiotics. Persons with severe valvular destruction may
require valve replacement.
is extremely important because infective endocarditis is so difficult
to treat and can cause severe disability or death. All persons
with evidence of valvular injury or deformity should take preventative
antibiotics before dental or surgical procedures are performed.
If you have a known heart murmur or valvular problem consult your
dentist and doctor prior to dental or surgical procedures.
muscle dysfunction ( papillary muscles do not work properly) may
occur from a heart attack, cardiomyopathy or congestive heart failure.
This can cause regurgitation to occur across the tricuspid or mitral
valves. Rupture of a papillary muscle (usually after a heart attack)
may cause sudden regurgitation of blood back into the lungs. This
may cause severe breathing problems due to excess fluid in the lungs-
this is called congestive heart failure.
aortic stenosis is a degenerative condition that is the most common
cause of aortic stenosis in people over 70. Calcium
deposits cause narrowing of the aortic opening. Blood flow to the aorta
is partially blocked causing the left ventricle to work harder. This
may eventually cause the left ventricle to weaken and not pump blood
valvular conditions (present at birth)
aortic valve ( aortic valve has 2 cusps instead of 3 cusps)
is the most common cause of aortic stenosis in
all people. Persons with a bicuspid valve often develop symptoms
in their 50's.
valve prolapse (click murmur syndrome)is a condition that has
caused much debate and controversy in the medical community. Mitral
valve prolapse (MVP) occurs when one or both of the mitral valve leaflets
push back (bow) into the left atrium during contraction of the left
ventricle. MVP is probably only important if a person has both excess
bowing of the mitral leaflets into the atrium and actual regurgitation
of blood from the left ventricle to the left atrium when the heart
use of echocardiogram (ultrasound of the heart)
over the past 20 years has revolutionized examination of the heart.
Using earlier ultrasound criteria it was estimated 5-10% of the
population has MVP. However, recent studies suggest that slight
bowing of the mitral valve (not accompanied by regurgitation) is
normal for many people and that MVP was likely over diagnosed because
of the ability of ultrasound to see extremely small variations in
the mitral valve shape. Using revised criteria it is believed that
MVP is present in less than 1% of the general population.
particularly women, with heart palpitations due
to anxiety often see a doctor and have heart evaluation (including
ultrasound) performed. Many persons with a panic (anxiety) disorder
were found to have mild mitral valve bowing on ultrasound- It was
believed that panic attacks were more common in people with mitral
valve prolapse. Newer studies suggest there is no correlation between
panic attacks and mitral valve prolapse. Most patients who had ultrasounds
and were diagnosed with MVP did not have true MVP but simply normal
variation in the shape of their mitral valve. For many patients
and physicians it may have been easier to accept that a physical
condition was responsible for panic attacks. Most people have no
symptoms of MVP.
with MVP having demonstrated regurgitation are
at slightly increased risk of developing endocarditis during dental/surgical
procedures and should receive antibiotic prophylaxis. A very
small number are at increased risk of sudden death.
valve normally allows one way flow of blood from the left atrium to
the left ventricle. Disorders of the mitral valve may cause mitral
valve stenosis, mitral valve regurgitation or mitral valve prolapse
Stenosis is narrowing of the mitral valve opening that usually
gradually occurs over time due chronic scarring. Rheumatic fever
is still the most common cause of mitral valve stenosis.
the mitral opening narrows the left atrium enlarges (dilates) over
time because it must work harder to pump blood into the left ventricle.
Many people (upto 50%) eventually develop atrial fibrillation
because of progressive dilatation of the left atrium. In atrial
fibrillation the left atrium quivers instead of effectively pumping
blood to the left ventricle causing a decreased amount of blood
to the left ventricle.
stenosis may also cause pressure to built up in the lung blood vessels
(pulmonary veins) that supply blood to the left atrium. The lung
blood vessels are normally under much lower pressure (as is the
right side of the heart that pumps blood to the lungs) than the
left ventricle, aorta and its' arterial branches. Increased blood
pressure in the lungs is called pulmonary hypertension.
may not appear for many years but are usually due to congestive
heart failure. The first ( and most common) symptom to appear
is usually shortness of breath (beyond normal) during physical
activity. Any stimulus that rapidly increases heart rate or blood
flow can cause sudden increase in lung congestion and cause shortness
of breath. Other factors responsible for shortness of breath in
those with mitral stenosis (in additional to physical activity)
include stress, fever, pregnancy, or onset of atrial fibrillation.
As the disease worsens shortness of breath at rest or while lying
down may occur. Severe disease is common with pulmonary
The second most common symptom to initially appear is coughing
up blood due to rupture of a bronchial (lung) vein.
clots are more likely to form in the left atrium during atrial
fibrillation - these blood clots (emboli) may dislodge and travel
to other body organs including the brain, eyes, heart and kidneys.
The risk of stroke or heart attack (due to emboli traveling to
the brain or coronary arteries) is higher in persons with atrial
of mitral stenosis is suspected in a person with a history of
congestive heart failure, findings of a specific type of mitral
heart murmur on physical exam, and suggestive
chest x-ray and EKG findings. Definitive diagnosis is made using
ultrasound- The entire valve can be visualized.
catheterization ( dye is injected into a blood vessel near the
heart and movie-like pictures taken) is performed if surgical
repair or replacement of the mitral valve is considered. Catheterization
will detect if there is narrowing of the coronary arteries. Coronary
artery disease increases the risk of heart attack during surgery
and may need to be corrected prior to surgical valve repair or
depends on the severity of symptoms, health and age of an individual,
amount of mitral valve narrowing, and whether coexisting aortic
valvular disease is present. Persons requiring treatment for this
disorder must be under the care of a physician!
treatment options include:
balloon mitral valvulotomy- a balloon tipped catheter is threaded
through an artery into the heart. The balloon is inflated to expand
the mitral valve. This technique has been very effective in younger
patients with valves that are not calcified (excessively stiff).
valvulotomy (commisurotomy)- the natural valve is widened by making
a cut in the mitral valve.
valve replacement- the mitral valve is replaced by a prosthetic
("artificial")valve. Valves may be either bioprosthetic
(pig, cow, or human) or synthetic (usually metal alloys). Valvular
replacement is usually required in older patients with heavily calcified
(stiff) mitral valves.
people have no symptoms the first 10 years, increasing shortness
of breath on exertion the next 10 years followed by worsening symptoms
that may begin to occur at rest during the next decade.
people having mitral stenosis of any degree require antibiotic prophylaxis
to prevent infective endocarditis prior to dental or surgical procedures.
Regurgitation occurs when blood flows back into the left atrium
from the left ventricle during left ventricular contraction because
of a "leaky" mitral valve. Mitral regurgitation can occur
acutely (suddenly) with infective endocarditis or with a heart attack
that causes rupture of the papillary muscles or chordae tendineae. Symptoms
of severe congestive heart failure ( severe shortness of breath, fast
heart rate, and fluid in the lungs) requiring urgent surgical intervention
usually occur with acute mitral valve rupture.
fever is the most common cause of chronic (gradual over many years)
mitral regurgitation. Chronic regurgitation, even with large regurgitant
blood flow, is often tolerated for years due to compensatory changes
in the heart. The left atrium dilates over time to handle the increased
are very similar to mitral stenosis. As with mitral stenosis the
most common first symptom is shortness of breath with exertion,
atrial fibrillation is common in later stages and the risk of emboli
is as high as 20%. Most emboli travel to tissues that do not cause
symptoms. However, emboli traveling to the brain may cause stroke
and emboli traveling to the coronary arteries may cause heart attack.
may be made by a person giving a history of shortness of breath
with exertion and the doctor hearing a heart murmur
suggestive of mitral regurgitation. As with all valvular disorders
definitive diagnosis is made with ultrasonography. Persons considered
for valvular repair or replacement will have cardiac catheterization
is similar to that for mitral stenosis except balloon valvuloplasty
is not performed unless the mitral valve is also stenotic. Most
cases of mitral regurgitation do not involve significant stenosis.
Valve replacement or reconstruction is indicated for most persons
with severe symptoms (shortness of breath at rest or with minimal
( blood thinning agents) is recommended for those with mitral regurgitation,
especially persons with atrial fibrillation, due to increased risk
of stroke from emboli.
The time course from the presence of this disease to the first symptoms
is similar to that for mitral stenosis.
people having mitral regurgitation require antibiotic prophylaxis
to prevent infective endocarditis prior to dental or surgical procedures.
valve normally allows one way flow of blood from the left ventricle
to the aorta. Disorders of the aortic valve may cause aortic valve stenosis
or aortic valve regurgitation.
Stenosis is narrowing of the aortic valve.
heart disease (bicuspid valve)- most common cause
heart disease- second most common
heart disease (calcific aortic stenosis)- most common in persons
over 70 years of age.
happens with aortic stenosis?
aortic valve narrows the left ventricle must work harder to pump the
same amount of blood through a narrower opening. The left ventricle
is the largest and strongest pumping chamber of the heart- it must
pump blood to the entire body. The left ventricular muscle increases
in size (hypertrophies) over time to compensate for the extra work
it must perform. The strength and ability of the left ventricle to
compensate for increased work load may mask the symptoms of aortic
stenosis for many years until the valve becomes extremely narrow.
When the aortic valve narrows past a certain point the left ventricle
can no longer fully compensate. Not as much blood can be pumped across
the aortic valve to the body, particularly during activities requiring
increased blood flow to the organs and muscles. At this point symptoms
of breath with exertion. This symptom may occur earlier in very
physically active people. This is usually the first symptom but
is not specific for aortic stenosis.
of breath awakening a person from their sleep (second most common
out (syncope) with exertion, angina, or heart attack are also common
and indicate severe disease.
gets aortic stenosis?
people do not develop symptoms until late in the course of aortic
stenosis. Age at onset of symptoms (clinically apparent aortic stenosis)
usually indicates the cause of aortic stenosis. Symptoms in people
younger than 30 years is almost always due to congenital causes (usually
bicuspid aortic valve). Symptoms in people 30-70 years may be due
to either bicuspid valve or rheumatic heart disease. Aortic stenosis
caused by rheumatic fever occurs 10-15 years later than mitral stenosis
caused by rheumatic fever. Symptoms developing in the elderly are
usually due to calcific degenerative changes of a normal aortic valve
(wear and tear of aging).
is aortic stenosis detected?
may see their doctor concerning symptoms of aortic stenosis. Chest
pain or passing out during exertion is very concerning and may prompt
a doctor into examining the heart in detail. If aortic stenosis is
present a certain type of heart murmur may be detected
when a doctor listens with a stethoscope. The doctor may order further
tests. Aortic stenosis can be definitively diagnosed using echocardiogram
fibrillation and traveling emboli are less common in isolated aortic
aortic stenosis serious?
symptoms develop aortic stenosis is very serious. The presence of
symptoms almost always means that the aortic valve is extremely narrow
and will not tolerate further narrowing. Once symptoms occur with
aortic stenosis, particularly angina or shortness of breath with minimal
exertion or congestive heart failure, many people die within several
years if not treated.
death, due to cardiac arrhythmias, may occur in
upto 20% of people with aortic stenosis. The cause of sudden death
is speculative (unknown).
is aortic stenosis treated?
and Tricuspid Valve Disorders
valvular disorders of the right side of the heart (receiving and pumping
venous blood to the lungs for oxygenation) are much less common than
left sided valvular disease. Combined left (mitral and/or aortic) and
right (tricuspid and/or pulmonic) heart valvular disease is more common.
Valve Disorders - Tricuspid valve normally allows one way blood
flow from the right atrium to the right ventricle.
tricuspid disease is most commonly due to endocarditis from IV drug
ventricular failure causing tricuspid regurgitation is usually due
to heart attack effecting the right ventricle
disease and left sided valvular disease due to rheumatic fever may
Valve Disorders - Pulmonic valve normally allows one way blood
flow from the right ventricle to the pulmonary (lung) arteries.
stenosis most frequently caused by a congenital defect (Tetralogy
of Fallot) that is detected and surgically corrected in infancy.
regurgitation (incompetence) is most commonly due to
of breath, particularly while laying flat are the most common initial
symptoms of tricuspid and pulmonary valve disorders. Symptoms of
worsening disease, in addition to shortness of breath, include swelling
of the feet, liver, abdomen or neck veins due to fluid retention.
valves are placed in over 40,000 persons a year in the United States.
There are more than six dozen types of valves. Prosthetic valves can
be grouped into two main categories:
(nontissue models) usually made of metal or composite alloys.
valves(bioprostheses) made from pig, cow or human valves.
of individual valve types is beyond the scope of this article. Readers
having questions about specific valve types or technical details must
consult with their doctor, cardiologist or cardiothoracic surgeon. Patients
with prosthetic valves should always carry a card that describes their
type of problems occur with prosthetic valves?
common in patients having more advanced heart disease (cardiomyopathy,
congestive heart failure, and/or arrhythmias) at
time of valve replacement.
valves may be slightly narrow (stenotic). A small amount of regurgitation,
due to incomplete closing, is common.
(blood clots) can form on prosthetic valves. If thrombi become large
enough they can interfere with blood flow or prevent the valve from
can embolize. This is the most important complication of mechanical
(nontissue) valves. This occurs in about 1% of people per year with
mechanical valves. This is not as common in tissue valves. Those with
mechanical valves almost always need to take blood thinning medications
(anticoagulation). Not all tissue valves require anticoagulation.
may gradually deteriorate.
valves often cause anemia due to increased red blood cell destruction.
mechanical valves can suddenly fail (break). This is often fatal.
is more likely to occur on artificial valves.
symptoms occur with prosthetic valve problems?
patients have ongoing shortness of breath and decreased exercise
tolerance after successful valve replacement. This is more likely
in persons with poorer heart function or atrial fibrillation.
with a sudden decrease in normal exercise tolerance or new chest pain
should see their doctor.
- In addition
to these symptoms people with prosthetic valve problems may experience
symptoms of emboli. Minor episodes (temporary) are common and can
include stroke like symptoms, abdominal pain (emboli blocking intestinal
blood vessels), and arm or leg pain (emboli blocking muscle blood
vessels). Major blockages can cause stroke, heart attack, and permanent
hemorrhage can occur during anticoagulation therapy. People on anticoagulants
noticing blood in the urine, feces, saliva or new skin bruising must
see their doctor.
with fever should see their doctor urgently. Fever could indicate
with prosthetic valves should receive antibiotic prophylaxis before
dental and surgical procedures.
atrium of heart ineffectively quivers instead of normally
beating of the heart that may cause the heart to beat too
fast or slow. Certain arrhythmias may cause the heart to
repetitive involuntary writhing movement of the head and
condition present at birth
heart can't pump enough blood to meet the needs of the body's
technique that views the heart valves using sound waves
and a computer generated image. Also called a heart ultrasound.
caused by turbulent blood flow across a heart valve(s) heard
by a doctor using a stethoscope.
are thin flexible flaps of connective tissue normally permitting
one-way blood flow through the heart.
uncomfortable awareness of the heart beating. May be slow,
normal or fast.
tough fibrous layer of tissue normally covering the heart.
Pericardial friction rub
sound heard with a stethoscope due to rubbing of the heart
against the pericardium that may occur with inflammation
of the pericardium.
pressure in the lung veins and arteries. These vessels
are normally under lower blood pressure than arteries
arising from the aorta and its' branches. May contribute
to or be caused by chronic congestive heart failure. Often
secondary to increased left atrial pressure, due to mitral
stenosis, causing blood to back up in the lungs.
flow of blood through a heart valve. Also called valvular
of the valve opening
ability of an infection to cause illness / injury to the