From the Guidelines
Tetralogy of Fallot is a congenital heart defect that requires surgical correction, typically performed within the first year of life, with a 30-year survival rate of over 90% 1.
Overview of Tetralogy of Fallot
Tetralogy of Fallot is characterized by four anatomical abnormalities: pulmonary stenosis, ventricular septal defect, overriding aorta, and right ventricular hypertrophy. This condition occurs due to abnormal development of the conotruncal septum during embryonic heart formation, leading to anterior and superior displacement of the infundibular septum 1.
Management and Treatment
Complete surgical repair involves closing the ventricular septal defect with a patch and relieving the obstruction to blood flow from the right ventricle to the pulmonary artery. Before surgery, infants may experience "tet spells" (hypercyanotic episodes) which can be managed acutely by placing the infant in a knee-chest position, administering oxygen, morphine, and propranolol 1.
Long-term Management
Long-term management includes regular cardiology follow-up, endocarditis prophylaxis for dental procedures, and monitoring for potential complications like arrhythmias, pulmonary regurgitation, or right ventricular dysfunction 1.
Key Considerations
- Patients with repaired tetralogy of Fallot should have at least annual follow-up with a cardiologist who has expertise in ACHD 1.
- Echocardiographic examinations and/or MRIs should be performed by staff with expertise in ACHD 1.
- Screening for heritable causes of their condition should be offered to all patients with tetralogy of Fallot 1.
- The most common problem encountered in the adult patient after repair is that of pulmonary regurgitation, which can be managed with catheterization and potential interventions such as elimination of residual shunts or aortopulmonary collateral vessels, dilation of RVOT obstruction, and elimination of additional muscular or patch-margin VSD 1.
From the Research
Definition and Characteristics of Tetralogy of Fallot
- Tetralogy of Fallot is a cyanotic congenital heart disease characterized by four main anatomic features: a large ventricular septal defect (anterior malaligned), overriding aorta, right ventricular outflow obstruction, and right ventricular hypertrophy 2.
- The pathophysiologic effects of Tetralogy of Fallot are largely determined by the degree of right ventricular outflow tract obstruction (RVOT) and not the ventriculoseptal defect (VSD) 3.
- The occurrence of Tetralogy of Fallot is approximately 3.9 per 10,000 births 3.
Diagnosis and Treatment
- The refinement of fetal screening and echocardiography has led to an increase in prenatal diagnosis of Tetralogy of Fallot 2.
- Full surgical repair within the first year of life, either primary or after a palliative procedure, is the mainstay of therapy for Tetralogy of Fallot 2.
- Early total correction is the treatment of choice for Tetralogy of Fallot, and these patients with repaired Tetralogy of Fallot are increasingly seen in adult practice 4.
Complications and Long-term Care
- Long-term complications of surgical repair of Tetralogy of Fallot include arrhythmias, sudden death, and right ventricular aneurysm formation 5.
- Reoperation is necessary in approximately 5% of patients for residual ventricular septal defect, pulmonary regurgitation, or pulmonary stenosis 5.
- Tetralogy of Fallot is a lifelong disease that requires careful follow-up through adulthood with the potential for additional surgical and interventional procedures later in life 2, 6.