Congenital Heart Disease
Core concepts
Adult congenital heart disease questions emphasize shunt physiology, cyanosis, murmurs, and complications. ASD causes a fixed split S2 and right-heart volume overload; VSD causes a holosystolic murmur; PDA causes a continuous murmur. Tetralogy of Fallot includes VSD, RV outflow obstruction, overriding aorta, and RV hypertrophy. Coarctation presents with upper-lower extremity BP discrepancy and rib notching. Eisenmenger syndrome is irreversible pulmonary vascular disease with reversed shunt. Pregnancy in cyanotic congenital disease is high risk.
Question traps
Do not assume a murmur is innocent without assessing timing and maneuvers. A normal oxygen saturation does not exclude a shunt. Paradoxical embolism can occur with PFO or ASD. Endocarditis prophylaxis is limited to specific high-risk lesions. Repair timing depends on shunt size, pulmonary pressures, and symptoms.
Worked example / rule of thumb
A 35-year-old with exertional dyspnea, fixed split S2, and right ventricular enlargement likely has an ASD; closure is considered if pulmonary vascular resistance is not severely elevated. Rule: fixed split S2 points to ASD until proven otherwise.