Cardiac catheterization
Barium esophagography: Classic “E sign,” representing compression from the dilated left subclavian artery and poststenotic dilatation of the descending aorta
Chest radiography: Findings vary with the clinical presentation of the patient
Fetal echocardiography
Echocardiography (2-dimensional echocardiography, pulsed-wave Doppler, and color flow mapping): In older patients, surface echocardiography may not suffice, and magnetic resonance imaging (MRI), transesophageal echocardiography (TEE), or cardiac catheterization with angiogram may be necessary
MRI: This test is sensitive but expensive, time-consuming, and not universally available; it is seldom used as a primary diagnostic tool
Electrocardiography
