Medical ConditionsCardiac & respiratory: Tetralogy of Fallot
Medical ConditionsCardiac & respiratory: Tetralogy of Fallot
Tetralogy of Fallot
Also called: ToF
Overview
Board takeaway: Confirm repair status, residual defects, valves or conduits, and antithrombotic medicines before care; match prophylaxis and anesthesia to current anatomy and function.
A common cyanotic congenital heart defect associated with hypercyanotic (tet) spells before repair.
How does Tetralogy of Fallot affect dental management?
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Cardiology consult: repair status, residual defects, prosthetic valves/conduits, medications, and activity tolerance.
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Warfarin: If taking warfarin, obtain the relevant INR plan; INR does not measure all antithrombotic medicines.
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Prophylaxis: Endocarditis prophylaxis for qualifying anatomy and procedures: amoxicillin 50 mg/kg orally, maximum 2 g, as a single dose 30–60 minutes before; assess allergy and alternatives as below
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Prevention: Prioritize sustained plaque control and prevention: daily oral activities can produce bacteremia, so an isolated prophylactic antibiotic dose does not replace oral health maintenance
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Emergency: Tet spell: knee-chest position, 100% oxygen, activate EMS
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Anesthesia: Sedation and GA in a hospital setting with cardiac anesthesia for unrepaired or complex disease
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Antithrombotic changes: do not stop or reduce prescribed anticoagulants or antiplatelets independently. Most routine dental procedures can use local hemostasis; higher bleeding risk or extensive surgery needs a prescriber-directed plan. ADA: medication management.
Exam pearl
What is Tetralogy of Fallot?
A congenital heart defect comprising four abnormalities: a ventricular septal defect, right ventricular outflow obstruction (usually pulmonary stenosis), an overriding aorta, and right ventricular hypertrophy.
What are the main systemic features of Tetralogy of Fallot?
- Four defects: VSD, pulmonary stenosis (RV outflow obstruction), overriding aorta, RV hypertrophy
- Associated syndromes: Associated with DiGeorge (22q11.2 deletion), Down syndrome and Alagille syndrome
- Presentation: Cyanosis, clubbing, murmur, poor growth; squatting relieves symptoms
- Tet spells: sudden hypercyanosis with agitation, feeding or crying
- After repair: Complete surgical repair in infancy; lifelong cardiology follow-up for arrhythmia and pulmonary regurgitation
What oral findings occur in Tetralogy of Fallot?
- Caries and enamel: Enamel hypoplasia and high ECC risk (sugary medications, frequent feeds, illness)
- Cyanosis and eruption: Bluish mucosa and tongue in unrepaired disease; delayed eruption
- Bleeding: Gingival bleeding on anticoagulants or antiplatelets
For Tetralogy of Fallot, which congenital heart disease qualifies for prophylaxis?
- Unrepaired cyanotic CHD, including palliative shunts/conduits
- Complete prosthetic-material/device repair during first 6 months
- Repaired CHD with residual defects at/adjacent to prosthetic material
- Other qualifying conditions: prosthetic valves, previous infective endocarditis, cardiac transplant with valvulopathy
For Tetralogy of Fallot, what is the antibiotic regimen for indicated infective endocarditis prophylaxis?
Give the indicated prophylaxis as a single dose 30–60 minutes before procedures that manipulate gingiva or the periapical region or perforate the mucosa.
- Amoxicillin: 50 mg/kg orally, maximum 2 g.
- Penicillin-allergy alternatives: cephalexin 50 mg/kg orally, maximum 2 g, or azithromycin/clarithromycin 15 mg/kg orally, maximum 500 mg.
- Cephalosporin exclusion: Do not use a cephalosporin when penicillin/ampicillin caused anaphylaxis, angioedema, or urticaria.
- Macrolide precautions: Review macrolide interactions and QT risk.
- Doxycycline: the AAPD 2026 IE-prophylaxis guidance lists 2.2 mg/kg below 45 kg and 100 mg above 45 kg when penicillins, cephalosporins, or macrolides cannot be tolerated.
- Age and evidence: It does not impose an over-8-years cutoff and notes that courses under 21 days have not been associated with tooth discoloration in children under 8.
- Clindamycin: no longer recommended.
For a child weighing exactly 45 kg, confirm the dose with the prescribing clinician: the published table does not explicitly assign that boundary.
During an exam, an unrepaired toddler becomes agitated and deeply cyanotic. What is happening and what do you do?
A tet (hypercyanotic) spell.
- Calm the child.
- Place the child in the knee-chest position to raise systemic resistance and pulmonary flow.
- Give 100% oxygen and activate EMS.