Accuracy of cross-sectional echocardiography in diagnosis of aortopulmonary window

The first echocardiographic descriptions of the aortopulmonary window (APW) were case reports.^1,2 These observations were extended by Smallhorn et al,³ who described appearances of an isolated APW in 4 infants and compared these with appearances in 14 patients with a common arterial trunk and in 6 with a single pulmonary artery originating at the ascending aorta. In these reports,^1-3 diagnosis was also established by invasive investigation and did not include any patient who had APW with associated cardiac abnormalities. The publication of case reports as late as 1988 suggests that the echocardiographic diagnosis of even an isolated APW is not always straightforward,⁴ perhaps because the lesion may be confused with other structural abnormalities.⁵ There have been no reports of the accuracy of cross-sectional echocardiography for the prospective diagnosis of APW. We reviewed our experience since the cases previously described³ to determine the implications for clinical practice.