Tetralogy of Fallot (ToF)

Presentation

• Harsh systolic ejection murmur (pulmonary stenosis)
• Varying degrees of cyanosis ('pink' vs 'blue' tet)
• Tet spells (hypercyanotic episodes): profound cyanosis, crying, tachypnea

Workup

• Echocardiogram: confirms VSD, overriding aorta, RVOTO, RVH
• Chest X-ray: 'Boot-shaped' heart (coeur en sabot), decreased pulmonary vascular markings
• ECG: Right ventricular hypertrophy

Management & Tet Spells

• Tet Spell Management: Knee-chest position, 100% Oxygen
• Pharmacotherapy for spells: Morphine (reduces respiratory drive), IV fluid bolus, beta-blockers (propranolol)
• Severe cyanosis at birth: PGE1 infusion to keep ductus open
• Surgical strategies: Blalock-Taussig-Thomas (BTT) shunt for palliation, or primary complete repair

Extended Pharmacology & Critical Care

• Alprostadil (PGE1) continuous infusion: Start at 0.05 to 0.1 mcg/kg/min; monitor strictly for apnea, hyperthermia, and extreme vasodilation.
• Milrinone loading dose 50 mcg/kg over 15 mins (only if stable blood pressure), followed by 0.33 to 0.75 mcg/kg/min infusion.
• Strict I&O monitoring; maintain urine output > 1-2 mL/kg/hr using indwelling catheter if necessary.
• Maintain hematocrit > 35-40% via PRBC administration to optimize oxygen delivery in cyanotic lesions.
• Nursing: Q1 hour blood pressure monitoring (arterial line preferred), monitor for feeding intolerance indicating gut hypoperfusion.

Standardized Discharge & Follow-Up Criteria

• Adequate weight gain explicitly > 15-30g/day over a continuous 3-5 day period.
• Maintenance of temperature in an open crib with standard clothing for 48 hours.
• Successful completion of the 90-120 minute Infant Car Seat Challenge.
• Caregiver successfully completed CPR training, rooming-in, and independent medication administration.
• Referrals placed for High-Risk Infant Follow-Up Clinic, Early Intervention (PT/OT), and appropriate sub-specialists.

Diagnostic & Management Algorithm

• Tetralogy of Fallot 'Tet Spell' Relief: [START] Hypercyanotic episode -> [ACTION] Knees-to-chest position / calm infant -> [PHARMACOLOGY] Oxygen + Morphine + Fluid Bolus -> [DECISION] Still cyanotic? -> [YES] Esmolol/Propranolol -> [GOAL] Increase SVR, lower PVR

References

1. Apitz C, Webb GD, Redington AN. Tetralogy of Fallot. Lancet.