Congenital heart disease and adult congenital cardiology
The exam tests shunt physiology, duct-dependent lesions, timing of repair and the late complications that bring adults with congenital disease to clinic.
Shunt lesions
- Significant shunt when Qp/Qs exceeds 1.5 with low pulmonary vascular resistance.
- ASD: fixed split S2, RV dilation; secundum defects close percutaneously when right heart dilation is present.
- VSD: small restrictive defects are loud but benign; large defects cause infant heart failure.
- PDA: indomethacin or ibuprofen in preterm infants; device closure later.
- Eisenmenger syndrome: pulmonary vascular resistance exceeds systemic, shunt reverses, cyanosis develops. Avoid pregnancy, give endocarditis prophylaxis, manage hyperviscosity carefully.
Cyanotic and obstructive lesions
- Tetralogy of Fallot: VSD, overriding aorta, right ventricular outflow obstruction, RV hypertrophy; boot-shaped heart; repair at 3-6 months; late pulmonary regurgitation needs reintervention.
- Coarctation: upper limb hypertension, radio-femoral delay, rib notching, neonatal collapse when the duct closes; prostaglandin keeps the duct open.
- Transposition: duct-dependent, prostaglandin then arterial switch.
- Bicuspid aortic valve: screen the aorta for dilatation.
Adults with congenital heart disease
- Pregnancy risk using the modified WHO class; pre-pregnancy counselling and endocarditis prophylaxis where indicated.
- Fontan circulation: arrhythmia, protein-losing enteropathy, liver fibrosis, plastic bronchitis; avoid dehydration and high-altitude stress.
Worked example
A 25-year-old with a fixed split S2 and RV dilation has an ASD. If Qp/Qs exceeds 1.5 with low pulmonary resistance, device closure is appropriate.
Traps
- Equating murmur loudness with shunt size.
- Missing coarctation in a young hypertensive patient.
- Ignoring aortic surveillance in bicuspid valve disease.