What cardiac anomalies should be evaluated in an echocardiogram (echo) before clearing a child with Down syndrome for orchidopexy surgery?

Preoperative Echocardiographic Evaluation for Orchidopexy in Down Syndrome

All children with Down syndrome require a comprehensive echocardiogram before orchidopexy surgery, regardless of whether they have a normal cardiac physical examination, because physical examination alone has only 80% sensitivity and misses significant cardiac defects in approximately 20% of cases. 1, 2

Essential Cardiac Anomalies to Evaluate

Structural Defects (Most Critical)

• Atrioventricular septal defects (AVSD): The most common cardiac anomaly in Down syndrome, present in approximately 33-44% of cases with congenital heart disease. Complete AVSD carries higher perioperative mortality (13% vs 5%) and requires specific anesthetic considerations. 1, 2, 3

• Ventricular septal defects (VSD): Assess size (small vs moderate/large), location, and hemodynamic significance. Moderate to large VSDs may affect anesthetic management and perioperative risk. 1, 2

• Tetralogy of Fallot: Present in approximately 11-13% of Down syndrome children with cardiac disease. Evaluate degree of right ventricular outflow obstruction, VSD size, aortic override, and right ventricular hypertrophy. 1, 2

• Patent ductus arteriosus (PDA): Specifically assess for PDA persisting beyond 7 days of age, as this represents pathologic rather than physiologic shunting. 1, 2

• Atrial septal defects (ASD): Document size (moderate/large defects may require intervention) and hemodynamic significance. 4

Functional Assessment (Equally Important)

• Pulmonary artery hypertension: Children with Down syndrome develop pulmonary vascular disease earlier and more rapidly than other children. Use Doppler echocardiography to estimate pulmonary artery pressures and assess for elevated pulmonary vascular resistance. 1, 3

• Ventricular function: Evaluate both left and right ventricular systolic and diastolic function, as poor ventricular function significantly impacts perioperative risk. 1

• Valvular abnormalities: Assess all four cardiac valves for stenosis or regurgitation, including tricuspid valve dysplasia and mitral valve abnormalities commonly associated with AVSD. 1

Additional Echocardiographic Elements

• Chamber size and dilation: Document chamber dimensions and assess for cardiomegaly, which may indicate volume overload from shunts or valvular disease. 1

• Direction and degree of shunting: Use color and spectral Doppler to quantify shunt flow across septal defects and assess hemodynamic significance. 1

• Pericardial effusion: Rule out pericardial disease that could complicate anesthesia. 1

• Thrombus formation: Particularly important in children with cyanotic lesions or previous cardiac interventions. 1

Clinical Context and Timing

The echocardiogram should be performed even if the child had a normal neonatal echocardiogram, because cardiac lesions can evolve over time and screening echocardiography should be repeated in late adolescence and early adulthood due to high rates of residual defects and development of new valvular disease. 5

Physical examination findings are insufficient for clearance: Studies demonstrate that 15% of Down syndrome neonates with normal physical examinations have significant cardiac defects on echocardiography, with 60% of these requiring eventual surgery. The negative predictive value of normal physical examination is only 59%. 2

Common Pitfalls to Avoid

• Do not rely on absence of murmur: 30% of Down syndrome children with significant cardiac disease have no audible murmur on examination. 2

• Do not assume prior normal echo means current normal status: Cardiac defects can progress, particularly pulmonary hypertension and valvular disease. 5

• Do not skip Doppler assessment: Anatomic imaging alone is insufficient; hemodynamic assessment with Doppler is essential for evaluating shunt direction, pulmonary pressures, and valvular gradients. 1

Anesthetic Risk Stratification

The echocardiographic findings directly impact surgical risk assessment. Complete AVSD is associated with significantly higher perioperative mortality (13% vs 5% for other lesions), while other cardiac malformations in Down syndrome show similar surgical outcomes to children without Down syndrome when properly managed. 3

Pulmonary hypertension represents the highest perioperative risk and may contraindicate elective surgery until adequately treated, as children with Down syndrome are particularly susceptible to pulmonary hypertension crises during anesthesia. 1, 3