Tetralogy of Fallot Flashcards
What are the 4 heart defects here?
What are the effects of the pulmonary stenosis?
Why is the degree of pulmonary stenosis important to assess?
What are its risk factors?
➊ • VSD
• Overriding aorta – Aorta directly over VSD, so deoxygenated blood enters straight from the RV
• Pulmonary stenosis (RV outflow tract obstruction) – Ejection-systolic murmur
• RV Hypertrophy
➋ • Provides resistance against RV outflow, therefore encouraging flow through the VSD instead → Cyanosis
• RV tries harder to pump through this resistance → RV Hypertrophy
➌ It’s the main determinant of the severity of cyanosis
➍ • Rubella infection
• Maternal alcohol and diabetes
How does it present?
• Most diagnosed antenatally
• Ejection-systolic murmur
• Cyanosis
• Poor feeding and weight gain
• Tet Spells
Tet Spells:
What is it?
What is it caused by?
→ What can precipitate this?
How does it progress?
What’s its main management option?
→ How does this work?
What are the other options in its management?
➊ Intermittent episodes of Cyanosis and Tachypnoea where R-L shunt becomes temporarily worsened
➋ Increases in pulmonary resistance or decreases in systemic resistance e.g. when child is physically exerting themselves a lot, CO2 builds up and acts a systemic vasodilator
→ Walking, physical exertion or crying
➌ Can last minutes to hours and may resolve spontaneously, or it can lead to reduced consciousness, seizures and even death
➍ Vagal manoeuvres – Bend knees to chest
→ This increases systemic resistance, therefore encouraging blood to enter and stay in the pulmonary circulation
➎ • Prophylactic propranolol to relax the RV
• Other options:
‣ Supplementary O2
‣ IVF – increase pre-load and systemic resistance
‣ Phenylephrine infusion – increase systemic resistance
‣ Morphine – decrease respiratory drive for more effective breathing
‣ Sodium Bicarbonate – treat any metabolic acidosis that occurs
How is ToF managed in neonates?
• Prostaglandin infusion to maintain the Ductus Arterioles, therefore allowing blood to flow from aorta into pulmonary vessels
• Surgical repair
