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Thursday, January 14, 2010

Congenital Heart Abnormalities Lexicon

One out of 100 newborn babies are born with congenital heart defects. If you're an RT who works in a neonatal intensive care unit you'll learn these like the back of your hands. Yet even we small town hospital RTs should understand the basics of these defects. You never know what you might run into in your hospital's OB.

Note: The following information was obtained from the American Heart Association:

1. Coarctation of the Aorta:
  • The aorta is narrowed at some point.
  • Narrowing is called coarctation
  • Occurs in 8% of patients with heart anomalies
  • Left heart has to work twice as hard to pump freshly oxygenated blood through aorta and to rest of body
  • Etiology unknown
  • more common in boys, and in many cases not diagnosed until teen or adult (no symptoms until then)
  • Often associated with other anomalies of left side of heart, particularly the bicuspid valve (the valve between left ventricle and aorta) having only 2 leaflets instead of three
  • Usually diagnosed due to high blood pressure, lower pulses in groin, or heart murmur
  • Symptoms: cold feet, shortness of breath with exertion, chest pain
  • Severe coarctation will be repaired right away by surgery
  • May also be treated in older patients (over 40) due to high blood pressure and the possibility of causing large heart, dissection or rupture that may cause death.
  • Common surgery is to remove the coarctation part of aorta and reconnect the two ends
  • Another procedure is balloon angioplasty, where a balloon is inserted through the a vessel in the leg to the aorta and expanded to dilate the coartation and improve blood flow.
2. Tetralogy of Fallot : :Heart anomaly that consists of four features
  • A ventricular septal defect (a hole between the ventricles)
  • obstruction of blood flow from the right ventricle to the lungs (due to pulmonary stenosis or obstruction of pulmonary valve) are the most important. Sometimes the pulmonary valve isn’t just narrowed but is completely obstructed (pulmonary atresia).
  • the aorta (major artery from the heart to the body) lies directly over the ventricular septal defect (VSD)
  • the right ventricle develops hypertrophy (thickened muscle).
  • Because of the pulmonary stenosis, blood can’t get to the lungs easily, so the blood doesn’t get as much oxygen as it should
  • Because the aorta overrides the ventricular septal defect, blood from both ventricles (oxygen-rich and oxygen-poor) is pumped into the body
  • blood can travel across the hole (VSD) from the right pumping chamber (right ventricle) to the left pumping chamber (left ventricle) and out into the body artery (aorta).
  • People with unrepaired tetralogy of Fallot are often blue (cyanotic) because of the oxygen-poor blood that’s pumped to the body.
  • Causes: Genetic, down syndrome, unknown
  • Most patients are diagnosed with tetralogy of Fallot as infants or young children
  • Most adults with tetralogy of Fallot have had it repaired in childhood
  • Treatment: 1) Shunt to increase blood flow to lungs. The shunt is usually a small tube of synthetic material sewn between a body artery (or the aorta) and the pulmonary artery. Removed when complete repair done. 2) Complete repair: Closure of ventricular septal defect with a patch, removal or repair of obstructed pulmonary valve and maybe enlarging the pulmonary artery branches
  • Sometimes a tube (conduit) with a valve in it is placed between the right ventricle and the pulmonary artery.
  • The above surgeries may cause leaky pulmonary valve that may need to be repaired in adolescence.
  • Constant contact with cardiologist will be needed to monitor for complications
  • Depending on severity, some will have to limit activity
3. Atrial Septal Defect: (ASD)
  • An ASD is an opening or hole (defect) in the wall (septum) between the heart’s two upper chambers (atria).
  • This is called the ductus arteriosis, and is normal before birth. However, it usually closes on its own within the first few weeks of life.
  • If too large, may not close on own. Etiology unknown
  • Oxygenated blood travels from left ventricle to the right side of the heart
  • Some adults have a patent foramen ovale (PFO)
  • If the ASD is large, the extra blood being pumped into the lung arteries makes the heart and lungs work harder and the lung arteries can become gradually damaged.
  • If the hole is small, it may not cause symptoms or problems
    large hole may cause murmur
  • A hole in the heart
  • Most common congenital heart defect
  • Etiology unknown or may be part of another congenital heart defect
  • A ventricular septal defect (VSD) is a defect in the septum between the right and left ventricle
  • This allows freshly oxygenated blood to return right ventricle & back to the lungs
  • This causes heart to pump more blood
  • The heart, particularly left ventricle, becomes enlarged due to added workload
  • Causes increased blood pressure in pulmonary vasculature due to extra blood that may damage blood vessel walls
  • If hole is small enough little blood will cross and there will be little complications
  • Many holes will close on their own over time
  • Most children have shortness of breath which is indication for surgery to repair hole.
  • Patients with closed hole and normal pulmonary artery pressure have normal lifespan
5. Mitral Valve Prolapse:
  • a very common heart condition
  • occurs when one of the heart's valves doesn't work properly
  • can be frightening because it involves the heart and can cause sharp chest pains, but it isn't a critical heart problem or a sign of other serious medical conditions.
6. Tricuspid Atresia:
  • there’s no tricuspid valve so blood can’t flow normally from the right atrium to the right ventricle
  • As a result, the right ventricle is small and not fully developed
  • As a result, the low-oxygen (bluish) blood that returns from the body veins to the right atrium flows through the atrial septal defect and into the left atrium
  • There it mixes with oxygen-rich (red) blood from the lungs
  • Most of this partially oxygenated blood goes from the left ventricle into the aorta and on to the body
  • A smaller-than-normal amount flows through the ventricular septal defect into the small right ventricle, through the pulmonary artery, and back to the lungs
  • Because of this abnormal circulation, the patient with this condition looks blue (cyanotic) until surgery can be performed
7. Hypoplastic Left Heart Syndrome (HLHS):
  • the heart’s left side — including the aorta, aortic valve, left ventricle and mitral valve — is underdeveloped.
  • Blood returning from the lungs must flow through an opening in the wall between the atria (atrial septal defect).
  • The right ventricle pumps the blood into the pulmonary artery,
  • and blood reaches the aorta through a patent ductus arteriosus.
  • The series of operations are similar to those done in other patients with single ventricles; however the first operation (Stage I Norwood) is more complicated than for other patients with single ventricles
  • Etiology: unknown
  • Without early intervention many patients die in infancy.
  • Almost all adults with single ventricles have had at least one, and in many cases, two or three operations in childhood.
    A procedure called a shunt is done to increase blood flow to the lungs in the first week of life
  • This improves the cyanosis
  • There are a series of surgeries to repair HLHS you can read about here.
  • Many patients with surgery have lived several decades with good life function
8. Pulmonary Atresia/Intact Ventricular Septum:
  • no pulmonary valve exists
  • Blood can’t flow from the right ventricle into the pulmonary artery and on to the lungs.
  • The right ventricle and tricuspid valve are often poorly developed.
  • An opening in the atrial septum (Patent Ductus Arteriosis or PDA) lets blood exit the right atrium, so low-oxygen (bluish) blood mixes with the oxygen-rich (red) blood in the left atrium. The only source of lung blood flow
    The left ventricle pumps this mixture of oxygen-poor blood into the aorta and out to the body.
  • The infant appears blue (cyanotic) because there’s less oxygen in the blood
  • Some patients with pulmonary atresia/intact septum can have a repair that allows the right ventricle to grow and function in a more normal way
  • If the pulmonary artery and right ventricle are very small, the patient may require the same type of operation as other single ventricle patients (see HLHS above)
9. Transposition of Great Arteries:
  • the aorta and pulmonary artery are reversed.
  • The aorta receives the oxygen-poor blood from the right ventricle, but it’s carried back to the body without receiving more oxygen.
  • Likewise, the pulmonary artery receives the oxygen-rich blood from the left ventricle but carries it back to the lungs.
  • Patients with transposition of the great arteries require surgery early in life to survive
  • Many infants undergo a procedure to enlarge ductus arteriosis to let blood mix so some oxygen rich blood can get to aorta and to vital organs. This is done to buy time for more invasive procedure when infant is ready.
  • Two procedures are available to correct this problem:
  • 1) Mustard procedure: creates a tunnel (a baffle) between the atria so unoxygenated blood gets to left ventricle and to the lungs, and oxygenated blood gets to right ventricle and aorta to body.
  • 2) Atrial switch operation: The aorta and pulmonary artery are switched back to their normal positions. Coronory arteries also need to be reattached to the new aorta
  • Constant contact with cardiologist will always be needed as future complications are possible.
  • The mustard procedure may result in decline in right heart function and valve failure
  • The Atrial switch procedure may result in better heart function but may have leakage or coronory artery problems
  • Arrythmias are common with either procedure
  • If heart too slow pacemaker may be indicated
  • Physical activity should be limited
10. Pulmonary Atresia:
  • No pulmonary valve exist, so no blood can get to lungs
  • The right ventricle and tricuspid valve are often poorly developed.
  • Etiology unknown (Tetrology of Felot)
  • PDA allows blood to exit right atria to left atria so unoxygenated blood mixes with oxygenated blood
  • Infant is blue
  • If PDA closes blood to lungs greatly diminished
  • Early treatment is drugs to keep PDA open
  • A surgeon can create a shunt between the aorta and the pulmonary artery that may help increase blood flow to the lungs.
  • If the pulmonary artery is large enough, surgery can be done to correct the problem
  • If the right ventricle stays too small to be a good pumping chamber, the surgeon can connect the body veins directly to the pulmonary arteries.
  • The atrial defect also can be closed to relieve the cyanosis.
  • These surgeries are called the Glenn and Fontan procedures.
  • Children with pulmonary atresia may be advised to limit their physical activities to their own endurance
11. Total Anomalous Pulmonary Venous Connection (TAPVC):
  • the pulmonary veins that bring oxygen-rich (red) blood from the lungs back to the heart aren’t connected to the left atrium
  • Instead, the pulmonary veins drain through abnormal connections to the right atrium.
  • Etiology: unknown
  • In the right atrium, oxygen-rich (red) blood from the pulmonary veins mixes with low-oxygen (bluish) blood from the body
  • Part of this mixture passes through the atrial septum (atrial septal defect) into the left atrium.
  • From there it goes into the left ventricle, then into the aorta and out to the body.
  • The rest of the blood flows through the right ventricle, into the pulmonary artery and on to the lungs
  • The blood passing through the aorta to the body doesn’t have a normal amount of oxygen, which causes the child to look blue.
  • Symptoms may develop at birth, sometimes they are delayed depending on severity
  • Severe obstruction of the pulmonary veins tends to make infants breathe harder and look bluer (have lower oxygen levels) than infants with little obstruction.
  • This defect must be surgically repaired in early infancy
  • At the time of open-heart surgery, the pulmonary veins are reconnected to the left atrium and the atrial septal defect is closed.
  • Children with repaired TAPVC may be advised to limit their physical activities to their own endurance
  • Long term outlook is good with surgery
12. Ebstein's Anomaly:
  • tricuspid valve is abnormally formed (valve between right atria and right ventricle)
  • one or two of the three leaflets are stuck to the wall of the heart and don't move normally.
  • Usually there is a patent ductus arteriosis
  • If the tricuspid tvalve leaks, some of the blood pumped by the right ventricle goes backwards through the valve with each heartbeat.
  • In some children, the right ventricle downstream from the tricuspid valve is smaller than normal and doesn’t work properly.
  • Ebstein's anomaly is mild in many children that they don’t need surgery
  • Surgery required if leaks too much. This can result in heart failure and cyanosis
  • It's complicated, but valve can often be repaired (PDA is closed at same time)
  • Most can participate in most sports. However, if severe enough, a cardiologist may recommend not participating in some activities.
13. Truncus Arteriosis:
  • two large arteries carrying blood away from the heart don’t form properly and one large artery is present instead
  • This artery (the truncus) sits over a large opening or hole in the wall between the two pumping chambers (ventricular septal defect).
  • This single great vessel carries blood both to the body and to the lungs.
  • Surgery is necessary to close the ventricular septal defect and separate blood flow to the body from blood flow to the lungs
  • This is usually done early in infancy to prevent high blood pressure from damaging the lung arteries
  • A patch is used to close the ventricular defect.
  • The pulmonary arteries are then disconnected from the single great vessel (the truncus) and a tube (a conduit or tunnel) is placed from the right ventricle to the pulmonary arteries
  • This is sometimes called a Rastelli repair.
  • Conduit may have to be replaced over time
  • Child can play in some sports if symptoms are minimal
14. Aortic Valve Stenosis (AS) and Aortic Insufficiency (AI):
  • The aortic valve opens to let blood flow from the main left pumping chamber (left ventricle) to the main body artery (aorta).
  • Narrowing of aorta makes left heart pump harder (AS)
  • Blood is regurgitated back through the Mitral valve into right aria between heartbeats (AI)
  • Some children have one or the other, some have both
  • Caused due to tricuspid valve with one or two leaflets instead of three
  • Etiology: unknown (may be in conjunction with other heart anomalies)
  • AS = heart works harder = large left heart (hypertrophy)
  • Mild = no symptoms. Severe = chest pain, unusual tiring, dizziness or fainting may occur.
  • If necessary, The valve can be treated to improve the obstruction and leak, but the valve can’t be made normal
  • Treatment for AS: treat left ventricular high blood pressure
  • AS can be treated be relieved during cardiac catheterization by balloon valvotomy. The balloon is inflated for a short time to stretch open the valve (called a valvotomy).
  • If AI is severe, or if leakage occurs, valve can be replaced (click here)
  • If no leak, there will be no physical restrictions
15. Pulmonary Stenosis (PS):
  • The pulmonary valve opens to let blood flow from the right ventricle to the lungs
  • Narrowing of the pulmonary valve (valvar pulmonary stenosis) causes the right ventricle to pump harder to get blood past the blockage
  • Etiology: unknown
  • High pressure in right ventricle may cause damage over time due to overworked right heart
  • Severe = cyanosis. Mild = no symptoms
  • The pulmonary valve can be treated to improve the obstruction and leak, but the valve can’t be made normal.
  • Medicine can relieve pressure in right ventricle
  • Cardiac cath can insert a balloon to dilate the pulmonary artery
  • Mild, or resolved with cath, no limits on activity
16. Atrioventricular Canal Defect:
  • A large hole between the atria and ventricles.
  • The Bicuspid and Tricuspid valves do not form properly, and one valve covers the hold
  • Blood travels from left ventricle to right ventricle.
  • This forces extra blood to lungs, and forces right heart to work extra hard to pump blood to lungs.
  • This can cause damage to lung blood vessels over time
  • A child with AV canal defect may breathe faster and harder than normal.
  • Infants may have trouble feeding and growing at a normal rate.
  • Symptoms may not occur until several weeks after birth
  • Regurgitation may occure too causing heart to work harder too.
  • Surgery is needed to fix valve
  • If severe enough, a band may be needed to narrow pulmonary artery to decrease blood flow to lungs
  • In adolescence, the band is removed and surgery done to repair valves
  • Some children may need to limit activity.

3 comments:

trinityheart8891 said...

Thanks Rick for posting this, good to know (I get the whole small hospital thing, I've already had a few suspected CHD babies) but also thanks for the awareness... ;)

Anonymous said...

Rick,

Thanks for this too.

Melissa

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