Chart — Pediatrics
Cyanotic vs Acyanotic Heart Defects Chart
Every congenital heart defect sorts into two columns by what its abnormal blood flow does. Left-to-right floods the lungs and looks like heart failure; right-to-left skips the lungs and looks blue. Learn the split and the defect names fall into place.
Educational use only. Defect-specific management, prostaglandin use, and oxygen targets are individualized — follow cardiology orders and your facility’s pediatric protocols. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Side by Side
| Feature | Acyanotic (L→R / obstructive) | Cyanotic (R→L / mixing) |
|---|---|---|
| Shunt / flow | Left-to-right (oxygenated blood recirculates to lungs); or obstruction to outflow | Right-to-left or mixing (deoxygenated blood reaches the body) |
| Color | Pink — but lungs and right heart overloaded | Blue (cyanosis), worse with crying/exertion |
| Classic picture | Heart failure: poor feeding, diaphoresis with feeds, tachypnea, failure to thrive | Hypoxemia: cyanosis, clubbing, polycythemia, tet spells, squatting |
| Defects in this group | VSD (most common), ASD, PDA, AV canal; obstructive: coarctation, aortic/pulmonic stenosis | The 5 Ts — Tetralogy of Fallot, Transposition, Tricuspid atresia, Truncus arteriosus, TAPVR |
| Signature finding | PDA — continuous machine-like murmur; coarctation — strong arm pulses/BP, weak femoral pulses | TOF — tet spells relieved by knee-chest/squatting; transposition — needs mixing (PGE1) to survive |
| Key management | Treat heart failure (digoxin, diuretics), high-calorie feeding; close PDA with indomethacin; surgical/catheter repair | Keep ductus OPEN with PGE1 in ductal-dependent lesions; knee-chest for tet spells; surgical correction |
| Oxygen caution | Generally tolerated | In ductal-dependent lesions O₂ can constrict the ductus and worsen flow — use ordered targets |
Exam Traps
- ✦Sort the defect by shunt FIRST — acyanotic = heart-failure picture, cyanotic = blue. The rest follows.
- ✦Cyanotic defects = the 5 Ts: Tetralogy, Transposition, Tricuspid atresia, Truncus arteriosus, TAPVR.
- ✦PGE1 keeps the ductus OPEN (ductal-dependent cyanotic lesions); indomethacin CLOSES a PDA. Opposite jobs, same vessel.
- ✦Tet spell → knee-chest position first; the squatting toddler is self-treating.
- ✦Coarctation: high BP and bounding pulses in the arms, weak femoral pulses and cool legs — compare upper and lower.
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with American Academy of Pediatrics (AAP) · CDC / ACIP (immunization schedule). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →