ABIM ACHD cheat sheet

Congenital heart disease affects approximately 8–9 per 1,000 live births; including bicuspid aortic valve, prevalence approaches 1%–2% of the population.

Ventricular septal defect is the most common lesion at birth; bicuspid aortic valve is the most common cardiac anomaly overall.

About 25% of congenital heart disease is critical, requiring intervention or surgery within the first year of life.

Recurrence risk is approximately 3% with one affected first-degree relative and rises to 10%–15% for left-sided lesions in siblings.

22q11.2 deletion occurs in 1:3,000–1:4,000 births and is associated with conotruncal defects, including tetralogy of Fallot, truncus arteriosus, and interrupted aortic arch.

Trisomy 21: 40%–50% have congenital heart disease, with atrioventricular septal defect the most characteristic lesion.

Turner syndrome is associated with bicuspid aortic valve and coarctation; Marfan syndrome results from FBN1 mutation and causes aortic root dilation.

Maternal diabetes increases congenital heart disease risk three- to five-fold; maternal rubella is linked to patent ductus arteriosus and pulmonary artery stenosis.

More than 90% of children with congenital heart disease now survive to adulthood, and adults with congenital heart disease outnumber children.

Atrial septal defect: left-to-right shunt causes right atrial and ventricular volume overload; closure is indicated when Qp:Qs exceeds 1.5 with pulmonary vascular resistance less than one-third systemic.

Ventricular septal defect: small restrictive defects produce a loud holosystolic murmur and often close spontaneously; large unrestrictive defects cause heart failure and pulmonary hypertension.

Tetralogy of Fallot comprises ventricular septal defect, overriding aorta, right ventricular outflow tract obstruction, and right ventricular hypertrophy; squatting raises systemic vascular resistance and reduces right-to-left shunting.

Transposition of the great arteries creates parallel circulations; survival depends on mixing through an atrial septal defect, ventricular septal defect, or patent ductus arteriosus, and untreated first-year mortality approaches 90%.

Obstructed total anomalous pulmonary venous return causes neonatal cyanosis and pulmonary edema and constitutes a surgical emergency.

Ebstein anomaly: apical displacement of the septal tricuspid leaflet causes tricuspid regurgitation, right atrial enlargement, and Wolff-Parkinson-White syndrome.

Coarctation of the aorta: upper-extremity hypertension, delayed femoral pulses, and rib notching; bicuspid aortic valve coexists in up to 50%–75%.

Eisenmenger syndrome: pulmonary vascular disease reverses a long-standing shunt, producing cyanosis; pregnancy carries 30%–50% maternal mortality.

Fontan circulation provides passive pulmonary blood flow; late complications include atrial arrhythmia, protein-losing enteropathy, plastic bronchitis, and Fontan-associated liver disease.

Echocardiography is first-line for anatomy, shunt direction, valve function, and estimation of right ventricular systolic pressure from the tricuspid regurgitation jet.

Cardiac MRI is the reference standard for ventricular volumes, ejection fraction, flow quantification, and myocardial fibrosis in adult congenital heart disease.

Cardiac CT is preferred when MRI is contraindicated and for coronary anomaly assessment or calcium scoring.

Qp:Qs = (SaO2 − MvO2)/(PvO2 − PaO2) using oxygen saturations; a ratio greater than 1.5 denotes a hemodynamically significant shunt.

Pulmonary vascular resistance = (mean pulmonary artery pressure − pulmonary capillary wedge pressure)/cardiac output, expressed in Wood units.

ECG in secundum atrial septal defect: incomplete right bundle branch block and right axis deviation; in Ebstein anomaly: tall P waves, right bundle branch block, and delta waves.

Chest radiograph: boot-shaped heart in tetralogy of Fallot, snowman silhouette in total anomalous pulmonary venous return, egg-on-a-string in transposition, and rib notching in coarctation.

Newborn pulse oximetry screening after 24 hours detects critical congenital heart disease with moderate sensitivity and high specificity.

Cardiac catheterization quantifies shunt fraction, pulmonary vascular resistance, and chamber pressures and is required before considering closure of a shunt with borderline pulmonary hypertension.

Prostaglandin E1 maintains ductal patency in ductal-dependent lesions such as transposition, pulmonary atresia, interrupted aortic arch, and hypoplastic left heart syndrome; apnea and hypotension are adverse effects.

Balloon atrial septostomy (Rashkind) enlarges the interatrial communication to improve mixing in transposition of the great arteries and obstructive lesions with a restrictive atrial septum.

Device closure is standard for secundum atrial septal defect and patent ductus arteriosus; ventricular septal defect closure is selected by size, location, and shunt significance.

Tetralogy of Fallot repair combines ventricular septal defect closure with right ventricular outflow tract relief, usually at 3–6 months; pulmonary valve replacement is considered for severe regurgitation with right ventricular dilation.

The arterial switch operation is the preferred repair for transposition of the great arteries and is performed within the first weeks of life.

Endocarditis prophylaxis is limited to prosthetic valves or material, prior endocarditis, unrepaired cyanotic congenital heart disease, residual defects after repair, and the first six months after repair.

Pulmonary arterial hypertension: calcium channel blockers are used only in vasoreactive patients; endothelin antagonists, phosphodiesterase-5 inhibitors, and prostacyclins are used otherwise.

Mechanical valves require lifelong anticoagulation; bioprosthetic valves are preferred when future pregnancy is planned.

Heart failure therapy in adult congenital heart disease uses diuretics, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers, and aldosterone antagonists, though trial evidence is limited.

Down syndrome: atrioventricular septal defect and ventricular septal defect predominate; pulmonary hypertension risk is increased, so repair is often performed early.

22q11.2 deletion: hypocalcemia, T-cell deficiency, and airway anomalies complicate perioperative care.

Turner syndrome: coarctation and bicuspid aortic valve are common; aortic root dilation requires serial imaging and pregnancy risk counseling.

Marfan syndrome: beta-blockade or angiotensin receptor blockade is used, and aortic root replacement is recommended at 5.0 cm or 4.5 cm with risk factors.

Williams syndrome: supravalvular aortic stenosis and coronary ostial stenosis increase the risk of sudden death during anesthesia.

Noonan syndrome: dysplastic pulmonary valve stenosis and hypertrophic cardiomyopathy are characteristic findings.

Eisenmenger patients should avoid pregnancy, dehydration, high altitude, and systemic vasodilation.

Fontan patients require surveillance for arrhythmia, liver disease, protein-losing enteropathy, and plastic bronchitis.

Pregnancy increases plasma volume 40%–50% and cardiac output 30%–50% while systemic vascular resistance falls, with peaks in the second trimester and at delivery.

mWHO class IV lesions, including pulmonary arterial hypertension, severe systemic ventricular dysfunction, severe aortic stenosis, and aortic root greater than 4.5 cm, carry prohibitive maternal risk.

Eisenmenger syndrome carries 30%–50% maternal mortality, and pregnancy is contraindicated.

Warfarin is teratogenic; in mechanical valve recipients, low-molecular-weight heparin is often used in the first trimester with anti-Xa monitoring.

Fetal echocardiography at 18–22 weeks detects recurrent congenital heart disease; recurrence risk is approximately 3%–5%.

Vaginal delivery with epidural anesthesia is preferred, and cesarean section is reserved for obstetric indications.

Ergometrine causes vasoconstriction and is avoided; oxytocin is used cautiously because of its hemodynamic effects.

Endocarditis prophylaxis at delivery is given only for the standard high-risk cardiac indications.

Hypercyanotic spell: knee-chest position, supplemental oxygen, morphine, intravenous fluids, beta-blockade, and phenylephrine raise systemic vascular resistance and reduce right-to-left shunting.

Eisenmenger syndrome: avoid hypotension and vasodilation; supplemental oxygen and careful volume management are used.

Sudden chest or back pain in Marfan, Turner, or coarctation patients suggests aortic dissection and requires urgent CT angiography and blood pressure control.

Fontan failure: evaluate for arrhythmia, baffle obstruction, pulmonary embolism, and ventricular dysfunction.

Plastic bronchitis: airway casts cause severe hypoxemia; treatment includes inhaled fibrinolytics, steroids, and optimization of Fontan hemodynamics.

Endocarditis: obtain three blood culture sets before antibiotics and perform echocardiography.

Atrial flutter is common after the Fontan procedure and Mustard or Senning repair; cardioversion requires anticoagulation assessment.

Syncope in aortic stenosis or hypertrophic cardiomyopathy warrants urgent evaluation for arrhythmia and ischemia.

Cardiac arrest follows standard resuscitation, with attention to altered anatomy, shunts, and venous access after the Fontan procedure.

All adults with congenital heart disease need lifelong follow-up at a center with adult congenital heart disease expertise, with intervals determined by lesion complexity.

After tetralogy of Fallot repair, cardiac MRI is repeated every 3–5 years to assess right ventricular dilation and pulmonary regurgitation and to time pulmonary valve replacement.

Fontan surveillance includes annual liver enzymes, liver ultrasound, and elastography, with cardiac catheterization considered for hemodynamic deterioration.

Mechanical valve recipients require INR monitoring, with target ranges determined by valve type and position.

Bicuspid aortic valve and Marfan syndrome require serial aortic imaging, with surgical referral for diameter thresholds or rapid growth.

Vaccination against influenza, pneumococcus, and COVID-19 is recommended for adults with congenital heart disease, along with endocarditis prophylaxis education.

Exercise prescription is individualized; isometric strain is avoided in severe aortic stenosis and pulmonary arterial hypertension.

Transition programs during adolescence improve adherence, disease knowledge, and continuity of care.

Psychosocial, insurance, employment, and pregnancy planning issues are addressed during long-term follow-up.