Special Populations
The aging ACHD patient
The ACHD population is now dominated by adults, many over 60. Acquired disease - hypertension, coronary disease, diabetes, atrial fibrillation, degenerative valve disease - increasingly competes with the congenital lesion as the cause of symptoms and death. Do not automatically attribute new dyspnea or chest pain to the original diagnosis; evaluate for acquired disease with the same rigor.
Genetic and syndromic patients
Down syndrome brings atrioventricular septal defects, earlier pulmonary vascular disease, thyroid disease, and airway issues. 22q11.2 deletion brings conotruncal lesions, hypocalcemia, immunodeficiency, and psychiatric disease. Neurodevelopmental disability affects adherence and consent; involve caregivers and structured transition programs.
Fontan and transplant
Fontan patients need surveillance for arrhythmia, pathway obstruction, protein-losing enteropathy, plastic bronchitis, and hepatic complications including hepatocellular carcinoma. Transplant candidates require careful pulmonary vascular resistance assessment; some require combined heart-liver evaluation.
Transitions and noncardiac surgery
Structured transition from pediatric to adult congenital care reduces loss to follow-up. For noncardiac surgery, assess lesion severity, ventricular function, cyanosis, pulmonary hypertension, and anticoagulation, and involve ACHD cardiology early.
Traps
Missing acquired coronary disease in a patient with known CHD. Attributing cyanosis solely to Eisenmenger without checking for shunt thrombosis or anemia. Forgetting extracardiac associations such as hypocalcemia or thyroid disease. Assuming exercise limitation is inevitable rather than evaluating it.
Rule of thumb
In any adult with CHD, ask two parallel questions: what is the residual congenital lesion, and what has the patient acquired with age?
Pregnancy, ACHD Emergencies, and Long-Term Follow-Up
Pregnancy risk stratification
Use the modified WHO (mWHO) classes. Contraindicated or very high risk: pulmonary arterial hypertension including Eisenmenger syndrome (maternal mortality high), severe ventricular dysfunction (ejection fraction under 30%), severe symptomatic aortic or mitral stenosis, Marfan syndrome with aortic root 45 mm or greater, and severe unrepaired coarctation. Preconception counseling, ACHD-center care, and planned delivery are the interventions that change outcomes.
Anticoagulation
Mechanical valves carry the highest thrombotic risk. Warfarin is teratogenic in the first trimester (6–12 weeks); low-molecular-weight heparin avoids that risk but is less effective for mechanical valves. Decisions require shared discussion - exam items reward recognizing the trade-off, not a single universal answer.
Emergencies
Hypercyanotic spell in tetralogy: knee-chest position, oxygen, morphine, intravenous fluids, phenylephrine to raise systemic vascular resistance, and beta-blockade. Aortic dissection in Marfan or bicuspid aortopathy: imaging immediately, control blood pressure, call surgery. Fontan failure, conduit obstruction, shunt thrombosis, endocarditis, and atrial arrhythmia with hemodynamic compromise are all ACHD emergencies.
Long-term follow-up
Lifelong ACHD-center care is the standard, with surveillance intervals set by lesion complexity. Screen for aortic dilation, arrhythmia, ventricular dysfunction, pulmonary hypertension, and hepatic complications after Fontan, plus psychosocial and insurance needs.
Traps
Reassuring a patient with Eisenmenger physiology about pregnancy. Treating a hypercyanotic spell with a vasodilator or beta-agonist. Forgetting to image the aorta in dissection-capable aortopathy.
Rule of thumb
Any new symptom in an adult with CHD is an emergency until pulmonary hypertension, arrhythmia, dissection, or conduit failure is excluded.