para>Congenital disorder
Pregnancy Considerations
Pregnancy is usually well-tolerated following successful surgical repair.
EPIDEMIOLOGY
Incidence
- 5 " 10% of all congenital heart disease (1)
- Most common cardiac anomaly within the 1st year of life requiring intervention
- Predominant age: newborn; case reports of adult presentation
- Predominant sex: male = female
Prevalence
In the United States: 3.9/10,000 live births
ETIOLOGY AND PATHOPHYSIOLOGY
Unknown
Genetics
- Minority of cases are familial, autosomal dominant mode of inheritance.
- 20% association with velocardiofacial syndrome (22q11 deletion) by FISH analysis
RISK FACTORS
- Predominately sporadic
- Increased incidence with advanced maternal age
COMMONLY ASSOCIATED CONDITIONS
- Stenotic pulmonary artery
- Patent ductus arteriosus
- Atrial septal defect
- Right-sided aortic arch: 25%
- Atrial septal defect: 15%
- Anomalous coronary arteries: 9%
- 20 " 25% associated with a syndrome, including Down, Alagille, DiGeorge, and velocardiofacial
DIAGNOSIS
HISTORY
Presenting symptoms
- Exertional dyspnea
- Delayed development and growth
- Squatting position, typically following exertion and during "tet " spells (which reduces right-to-left shunting by increasing systemic vascular resistance)
PHYSICAL EXAM
- Findings depend on the severity of pulmonic stenosis and pulmonary insufficiency.
- "Pink " or acyanotic: due to mild RV-outflow tract obstruction, resulting in left-to-right shunt
- Cyanotic: due to severe RV outflow and tract obstruction with right-to-left shunt (generally recognized early in lips and nail beds)
- Normal arterial and jugular venous pulses
- Systolic thrill along the left sternal border
- Early systolic ejection sound (aortic)
- Single S2 (decreased P2)
- Crescendo " decrescendo systolic ejection murmur results from flow across narrowed RV outflow tract.
- Continuous soft murmur of bronchial collateral vessels (if diminutive pulmonary arteries)
- Clubbing and polycythemia in children secondary to hypoxia
DIFFERENTIAL DIAGNOSIS
- Tetralogy of Fallot with absent pulmonic valve
- Tetralogy of Fallot with absent pulmonary artery
- Pseudotruncus arteriosus
DIAGNOSTIC TESTS & INTERPRETATION
ECG
- Sinus rhythm
- Right atrial enlargement and RV hypertrophy
- Right-axis deviation and RV conduction abnormality may be seen.
- Chest radiograph
- Classic boot-shaped heart (coeur en sabot) with diminished pulmonary blood flow (infrequently seen with increased early diagnosis)
- Prominent RV
- Right-sided aortic arch and knob in 25% of patients
- Normal (or decreased) pulmonary vascularity in <50% of adults
- Transthoracic ECG (occasionally transesophageal)
- Ventricular septal defect, atrial septum, RV hypertrophy, and extent and location of the infundibular obstruction
- Overriding aorta and assessment of pulmonic valve
- Coronary anatomy and peripheral branch pulmonic arteries
Diagnostic Procedures/Other
Cardiac catheterization (rare prior to correction)
- Details anatomic structure (if not well seen on echo)
- Assesses pulmonary annulus size and pulmonary artery hypoplasia
- Assesses severity of RV outflow obstruction
- Locates position and size of primary ventricular septal defect
- Identifies possible additional ventricular septal defects
- Rules out coronary artery anomalies
- Balloon valvuloplasty to reduce pulmonary stenosis in complex cases
Test Interpretation
- Anterior and cephalad deviation of the infundibular septum results in malalignment with the muscular septum and creates a ventricular septal defect.
- Malposition of the infundibular septum encroaches on the RV outflow tract and results in an increased aortic root size.
- Aortic root rotated into overriding position
TREATMENT
GENERAL MEASURES
- Good dental hygiene
- Routine endocarditis prophylaxis is recommended until repair.
MEDICATION
- No specific chronic drug therapy in the absence of heart failure
- Acute therapy for "tet " spell depending on patient response
SURGERY/OTHER PROCEDURES
- Intracardiac repair is the preferred modality of treatment and includes closure of the ventricular septal defect, preservation of the RV, and relief of the RV outflow obstruction. Generally completed in the 1st year of life, sometimes in the first 3 months of life depending on cardiac anatomy and relative risk
- Palliative surgical therapy with a systemic-to-pulmonary shunt in complex cases: Blalock-Taussig shunt or modified shunt with Gore-Tex tubing; subclavian to pulmonary artery
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
Inpatient for diagnosis and surgery
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
As tolerated
Patient Monitoring
- Postprocedure echocardiography
- Monitor for postoperative complications.
- Good dental hygiene
DIET
Appropriate for age
PATIENT EDUCATION
American Heart Association, 7320 Greenville Avenue, Dallas, TX 75231; (214) 373-6300
PROGNOSIS
- Surgical correction yields a survival of 94% at 20 years and projected 90% at 40 years.
- Following surgical correction, pregnancy is usually well-tolerated, although RV function should be carefully monitored because of the increased volume load (2).
- Exercise should be limited by individual cardiovascular status, including concerns for arrhythmias, pulmonary regurgitation, and RV dilation.
COMPLICATIONS
- Anatomic-related
- Residual RV outflow obstruction
- Residual ventricular septal defect
- Chronic pulmonary regurgitation (with subsequent valve replacement)
- Ventricular and atrial tachyarrhythmias
- Right bundle-branch block (common)
- Left anterior hemiblock
- Aortic root dilation
- Neurodevelopmental impairment secondary to hypoxia
REFERENCES
11 Apitz C, Webb GD, Redington AN. Tetralogy of Fallot. Lancet. 2009;374(9699):1462 " 1471.22 Pandya B, Quail MA, Cullen S. Clinical issues and outcomes in adults following repair of tetralogy of Fallot. Curr Treat Options Cardiovasc Med. 2013;15(5):602 " 614.
ADDITIONAL READING
- Hickey EJ, Veldtman G, Bradley TJ, et al. Late risk of outcomes for adults with repaired tetralogy of Fallot from an inception cohort spanning four decades. Eur J Cardiothorac Surg. 2009;35(1):156 " 164.
- Miatton M, De Wolf D, Fran §ois K, et al. Intellectual, neuropsychological, and behavioral functioning in children with tetralogy of Fallot. J Thorac Cardiovasc Surg. 2007;133(2):449 " 455.
- Neal AE, Stopp C, Wypij D, et al. Predictors of health-related quality of life in adolescents with tetralogy of Fallot. J Pediatr. 2015;166(1):132 " 138.
- Pham P, Silberbach M. What 's new in pediatric cardiology. Pediatr Rev. 2004;25(11):381 " 387.
- Shinebourne EA, Babu-Narayan SV, Carvalho JS. Tetralogy of Fallot: from fetus to adult. Heart. 2006;92(9):1353 " 1359.
CODES
ICD10
Q21.3 Tetralogy of Fallot
ICD9
745.2 Tetralogy of fallot
SNOMED
- Tetralogy of Fallot (disorder)
- Ventricular septal defect in Fallot 's tetralogy
- Tetralogy of Fallot with pulmonary atresia (disorder)
- Tetralogy of Fallot with pulmonary stenosis (disorder)
CLINICAL PEARLS
- Age and symptoms at presentation can vary depending on the severity of the defect.
- Surgical correction has a high probability of providing a dramatic improvement in survival and outcome.