20. Congenital heart defect in children · Pediatrics · MU Sofia

20. Congenital heart defect in children.

Covers congenital heart defects in children, starting with their frequency and links to genetic syndromes and maternal factors, then working through acyanotic left-to-right shunts, obstructive lesions and cyanotic defects such as tetralogy of Fallot and transposition. Several comparison tables set out syndrome associations and the findings and treatment for each defect. It also explains newborn screening by pulse oximetry and the hyperoxia test, how to tell innocent murmurs from referable ones, and antibiotic prophylaxis for dental procedures in high-risk children.

Inside: 5 sections · 4 tables · 16 flashcards · 5 min

Topic 20 of 30 in the MU Sofia syllabus for Pediatrics (Medicine, Year 5). The free AceMed note covers it in 5 sections, about 339 words (5 min of reading), with 16 flashcards.

Introduction

Congenital heart defects (CHD) are the commonest birth defects: about 8 in 1000 live births. Most are multifactorial, but some come with syndromes or maternal factors. Many are now found on antenatal scans or by newborn pulse oximetry, and most can be repaired.

The main defects

Acyanotic, left-to-right shunts (more blood to the lungs)

Acyanotic, obstructive

Cyanotic (right-to-left or mixing)

Eisenmenger syndrome: a long-standing large left-to-right shunt damages the pulmonary vessels until pressure reverses the shunt, causing cyanosis. It is now rare because defects are closed early.

Finding heart disease in newborns

Pulse oximetry screening after 24 hours: pass if SpO₂ ≥ 95% in the right hand or a foot and the difference is ≤ 3%.
Always feel the femoral pulses.
Hyperoxia test: in 100% oxygen, arterial PaO₂ stays low (under about 150 mmHg) in cyanotic heart disease but rises in lung disease.

Innocent murmurs

Heard in up to half of children, louder with fever. Features: systolic (except the venous hum), soft, short, at the left sternal edge, changing with posture, normal heart sounds, no symptoms, normal pulses. Examples: Still's murmur (vibratory), pulmonary flow murmur, venous hum (continuous, disappears lying down). Refer if diastolic, loud (with thrill), with symptoms or in a newborn.