Download TETOLOGY OF FALLOT

TETRALOGY OF FALLOT (TOF)
Mary Beth Sanders BSN & Laura Durbin BSN
East Carolina University
College of Nursing, Greenville, North Carolina
Incidence and Risk
• occurs in 3 of every 10,000 live births.
• most common cause of cyanotic cardiac
disease in patients beyond the neonatal
age
• accounts for up to one-tenth of all
congenital cardiac lesions
• There are a number of state-based
programs monitoring CHDs among
newborns and young children, but
currently no population-based tracking
system exists to look at this growing
population of older children and adults
with heart defects.
• It is the least diagnosed CHD during the
prenatal period.
• Factors that increase the risk for this
condition during pregnancy include:
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Alcoholism in the mother
Diabetes
Mother who is over 40 years old
Poor nutrition during pregnancy
Rubella or other viral illnesses during
pregnancy
• Maternal intake of retinoic acid in 1st
trimester
• Associated conditions
• trisomies 21, 18, 13
• microdeletions of chromosome 22
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DiGeorge Syndrome.
• 3% risk of recurrence in a family
Surgical Treatment of TOF
Primary Repair
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VSD is closed
widening of the pulmonary valve or artery to increase
pulmonary blood flow.
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Pulmonary regurgitation is a complication patching to
pulmonary artery.
Severe cases may need pulmonary valve replacement
Ventricular arrhythmia is the most common long term
complication of repair
Blalock-Taussig procedure (temporary procedure)
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surgical construction of a shunt between the right subclavian
artery and the right pulmonary artery as a temporary
measure to increase pulmonary blood flow to the lungs.
Can be used as a palliative procedure to establish pulmonary
blood flow prior to primary repair.
Prostaglandin E (PGE)
• Stabilizes infants with severe cyanosis by
reopening or maintaining the ductus
arteriosus
• In most infants, the ductus will reopen within 30
minutes to 2 hours after starting PGE1
• Administered as a continuous IV infusion at
0.05-0.2 ug/kg/min.
• Side effects include
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Refractory hypotension from vasodilation
Apnea
Hyperthermia/ Flushing
Seizures
• Pharmacology
• Prostaglandins are long chain
unsaturated fatty acids produced by the
action of the enzyme clooxygenase and
are classified into groups E,D,A, F & B
• PGE is also produced in the kidney in response
to decreased renal blood flow  prevents
vasoconstriction and renal ischemia
• PGE vasodilates all arterioles, inhibits
platelet aggregation, and stimulates
uterine and intestinal smooth muscles.
Physiology of TOF
Four Different Defects In TOF
• large ventral septal defect: An opening between the 2 bottom
chambers of the heart.
• Pulmonary valve stenosis or atresia: Pulmonary blood flow
obstruction. This is due to a narrowing at the pulmonary valve or the
pulmonary arteries.
• Right ventricular hypertrophy: Caused by the heart working harder to
pump blood through the body because of the narrow pulmonary
valve.
Overriding aorta: The aorta overrides the ventral septal defect.
Tetralogy of Fallot
Pink TOF
Blue TOF
• Mild outflow tract obstruction
• Severe outflow tract obstruction
is present.
• Blood is shunted from left to right.
• Blood is able to enter the pulmonary
system thus, it is oxygenated.
• Infant is “pink”.
• Infants and children can experience
TET spells.
• Surgical repair is between 18 months
and 3 years old.
• Blood is shunted from right to
left.
• Pulmonary blood flow is
dependent upon R to L shunting
through the PDA.
• Infant will require PGE until
surgical repair is undertaken.
Radiographic Findings
in TOF
• Classic boot-shaped heart
• This finding is a result of
the upward lifting of the
apex of the heart.
• This is due to the
hypertrophy of the right
ventricle.
• The more pronounced the
upward lifting, the greater
the outflow obstruction is.
Blood Flow in Infants
with Tetralogy of Fallot
• Narrowing of the right
ventricular outflow tract at the
pulmonary artery.
• Deoxygenated blood is
prevented from entering
pulmonary system.
• Right ventricle hypertrophies
attempting to push blood
through stenosis.
• VSD allows shunting left to right
in mild stenosis “ pink” TET
Blood flow in infants
with Tetralogy of Fallot
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Cyanosis occurs when the right
tract outflow obstruction impedes
the blood flow significantly.
Blood in the right ventricle takes
the path of least resistance into
the left ventricle.
This creates a right-to-left shunt
Blood is directed away from the
pulmonary system
Blood leaves heart before being
oxygenated.
Thus, the infant is cyanotic.
References
• Bailliard, F., & Anderson, R. H. (2009, January 13). Tetralogy of Fallot. Orpanet journal of
rare diseases, 4. http://dx.doi.org/10.1186/1750-1172-4-2
• Buck, M. L. (2000). Alprostadil (pge1) for maintaining ductal patency. Pediatric
Pharmacotherapy, 6. Retrieved from http://www.medscape.com/viewarticle/410907_2
• Ferguson, E. C., Krishnamurthy, R., & Oldham, S. A. (2007). Classic imaging signs of
congenital cardiovascular abnormalities. RadioGraphics, 27, 1323-1334.
http://dx.doi.org/10.1148/rg.275065148
• Ismail, S. R., Kabbani, M. S., Najm, H. K., Abusuliman, R. M., & Elbarbary, M. (2010, April
). Early outcome of tetralogy of fallot repair in the current era of management. J Saudi
Heart Association, 22(2), 55-59. http://dx.doi.org/10.1016/j.jsha.2010.02.006
• Quek, S. C., & Lee, C. N. (2010). The modified blalock-taussig shunt revisited. Cardiology
in the Young, 20, 208-209. http://dx.doi.org/10.1017/S1047951109991041
References
• Martínez, J., Gómez, O., Bennasar, M., Olivella, A., Crispi, F., Puerto,
B., & Gratacós, E. (2010). The 'question mark' sign as a new
ultrasound marker of tetralogy of Fallot in the fetus. Ultrasound In
Obstetrics & Gynecology, 36(5), 556-560. doi:10.1002/uog.7614
• Westmoreland, D. (1999). Critical congenital cardiac defects in the
newborn. Journal Of Perinatal & Neonatal Nursing, 12(4), 67-87.
References
• Scholz, T. D., & Reinking, B. E. (2012). Congenital heart disease. In
Avery’s diseases of the newborn (9th ed., pp. 762-768). Phildelphia,
PA: Elsevier
• U.S. National Library of Medicine website. (2011).
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002534/
• Westmoreland, D. (1999). Critical congenital cardiac defects in the
newborn. Journal Of Perinatal & Neonatal Nursing, 12(4), 67-87.