Tetralogy of Fallot is a birth defect of the heart consisting of :
1. Pulmonic stenosis (narrowing of the pulmonary artery).
2. A ventricular septal defect (VSD). The VSD
causes cyanosis (bluish discoloration of the skin due to lack of oxygen) by allowing blood to flow from the right side of
the heart to the left side without passing through the lungs.
3. Malignment of the aorta so that it arises from the VSD or the right
ventricle instead of directly from the left ventricle
4. Right ventricular hypertrophy (thickening of the right heart chamber that pumps blood to the lungs).
Tetralogy of Fallot is typically an isolated sporadic malformation. If found
with other abnormalities then congenital syndromes such as trisomy 18, trisomy 13, de
Lange , Klippel-Feil, and CHARGE, should be considered. Up to 15% of patients with tetralogy of Fallot
have a chromosome
Some severely affected infants will require an operation shortly after birth to divert
(shunt) blood from the aorta to one of the pulmonary arteries in order to
improve oxygenation. Corrective surgery to close the VSD and enlarge the
narrowed areas of the right ventricle and the pulmonary valve and arteries is usually performed at
6 months. Overall survival after operative repair is excellent.
Persons with tetralogy of Fallot generally receive endocarditis prophylaxis
before dental or other surgical procedures. Long term, congestive heart failure
and abnormal atrial or ventricular arrhythmias (irregular heart beats) may
require treatment with medications in some patients.
Women with tetralogy of Fallot who
intend to become pregnant are usually assessed for functional status by their
cardiologist. In addition they usually will have had an echocardiogram to assess for residual ventricular
dysfunction, valvular function, and pulmonary hypertension. Women who have had repair and have good hemodynamic
status generally have successful term pregnancies. During pregnancy the mother
is examined regularly for complications such as anemia, hypertension, and
infection. The fetus is evaluated for congenital heart disease and may be
evaluated periodically for growth restriction . Vaginal delivery is preferred.
In general, advanced
New York Heart Association (NYHA) functional class and a prior history of heart failure
are risk factors for adverse cardiac outcomes in women with
congenital heart disease. In unoperated patients hypotension and large decreases in blood volume
(as occurs with cesarean delivery) will
exaggerate the right to left shunt worsening cyanosis. Unoperated pregnant patients or repaired patients with significant residual
right ventricular outflow tract (RVOT) obstruction, valve dysfunction, or
ventricular dysfunction are at high risk for right heart failure and arrhythmias
due to the increased volume load of pregnancy.
Khairy P, et al.,
Pregnancy outcomes in women with congenital heart disease.Circulation. 2006
;113(4):517-24. PMID: 16449731
Veldtman GR, et al.,Outcomes of pregnancy in women with tetralogy of Fallot.J Am Coll Cardiol. 2004
;44(1):174-80. PMID: 15234429
Meijer JM, et al.,
Pregnancy, fertility, and recurrence risk in corrected tetralogy of Fallot.Heart.