🧡 Congenital Heart Defects
Sort them by which way blood shunts. Left-to-right floods the lungs; right-to-left makes a blue baby.
⚖️ The one sorting rule
Ask which way the blood is going through the hole.
Left to right = too much lung blood = heart failure. Right to left = deoxygenated blood to the body = cyanosis.
| Group | Blood goes | Result | Examples |
|---|---|---|---|
| Acyanotic | Left → right | Pulmonary overload, heart failure, poor feeding, sweating, poor growth | ASD, VSD, PDA, coarctation, pulmonary stenosis |
| Cyanotic | Right → left | Cyanosis that oxygen does not fix | Tetralogy of Fallot, transposition, truncus, tricuspid atresia |
The memory hook: cyanotic lesions mostly begin with T or have a “T” sound — Tetralogy, Transposition, Truncus, Tricuspid atresia, Total anomalous pulmonary venous return.
🧠 Coarctation of the aorta
A narrowing of the aorta. The classic finding is a blood pressure difference:
- High blood pressure and bounding pulses in the ARMS
- Low blood pressure and weak or absent pulses in the LEGS
- Cool lower extremities; leg pain on exertion in older children
Always compare upper and lower limb pulses and pressures in a child with hypertension. Coarctation is a fixable cause that is missed by only checking an arm.
🔴 Tetralogy of Fallot
⭐ The four — PROV
- Pulmonary stenosis
- Right ventricular hypertrophy
- Overriding aorta
- VSD
🚨 The “tet spell”
Sudden deep cyanosis, usually triggered by crying, feeding or straining — anything that drops systemic resistance and sends more blood right-to-left.
Put the infant in the KNEE-CHEST position immediately. Older children squat instinctively - it does the same thing.
Why it works: flexing the hips raises systemic vascular resistance, which pushes blood back through the pulmonary artery to be oxygenated.
Then: calm the child, oxygen, morphine if ordered, IV fluids.
🩺 Heart failure in an infant
It looks like feeding trouble, not like adult heart failure.
- Sweating with feeds; tiring after a few minutes
- Poor weight gain — often the earliest sign
- Tachypnoea and tachycardia at rest
- Hepatomegaly — the pediatric equivalent of peripheral edema
- Periorbital edema rather than ankle swelling
Ankle edema is an adult sign. In a baby, look at the liver and the weight chart.
🍽️ Feeding a baby in heart failure
- Small, frequent feeds; limit each to about 30 minutes — longer burns more calories than it delivers
- Higher-calorie formula
- Feed at the first hunger cue, before crying exhausts them
- Cluster care to allow long rests
- Daily weights — the best measure of both nutrition and fluid
🚨 Digoxin in children
- Count the apical pulse for a full minute before every dose
- Hold and report: <90–110 in an infant, <70 in a child
- Early toxicity in a child is usually vomiting and bradycardia — not the visual changes adults get
- Watch potassium — low potassium worsens digoxin toxicity
Never repeat a dose that was vomited, and never mix digoxin into a bottle of formula - if the feed is not finished, the dose is unknown.
🩸 Kawasaki disease
Fever for 5 or more days plus red eyes, strawberry tongue, cracked lips, rash, and swollen red hands and feet that later peel.
It inflames coronary arteries and causes aneurysms, so treatment is IVIG plus aspirin — the one situation where a child is deliberately given aspirin.
After IVIG, live vaccines must be delayed about 11 months - the antibodies block the immune response.
🎯 NCLEX traps
- Left-to-right = failure. Right-to-left = blue.
- Tet spell → knee-chest immediately
- Coarctation: arms high, legs low — compare both
- Infant heart failure = sweating with feeds, poor weight gain, hepatomegaly
- Apical pulse for a full minute before digoxin
- Kawasaki is the exception where aspirin is given