Systemic venous abnormalities: embryologic and echocardiographic considerations.

The echocardiographic diagnosis of systemic venous anomalies often is rendered difficult by the variety of lesions that exist. An understanding of the embryologic processes that result in these lesions is essential for accurate identification, since these lesions often are not obvious on routine echocardiographic examination. Standard echocardiographic views may demonstrate some lesions, whereas many require modified views to outline the abnormal systemic venous anatomy. This paper reviews the basic embryologic processes of the development of the normal and abnormal systemic venous system, as well as the echocardiographic identification of these major systemic venous malformations.