[Echocardiographic diagnosis of infracardiac total anomalous pulmonary venous connection]

To investigate the clinical usefulness of echocardiography in the diagnosis of infracardiac total anomalous pulmonary venous connection (ITAPVC) in neonates and infants.

Retrospective analysis on 8 patients with ITAPVC was performed using echocardiography between April 2006 and December 2016. There were 4 boys and 4 girls with a mean age of 79.8 days (ranging from 15 to 195 days). A combined scanning via parasternal, subcostal and apical acoustic windows had been employed to diagnose ITAPVC and to trace the course and site of the anomalous pulmonary venous drainage, and to confirm the direction of the inter-atrial shunt and enlargement of right atrium and right ventricle.

Of the 8 patients who received echocardiography, ITAPVC was diagnosed in 7 patients. Mis-diagnosis by echocardiography was encountered in one patient. The diagnosis by echocardiography was compatible with the operative findings in 5 patients receiving surgery and with the results of multislice computed tomography in 6 patients. The diagnostic accuracy rate of ITAPVC was 87.5%. The indirect signs obtained from echocardiogram was coexistence of a small malformed, triangle-shaped left atrium and right to left shunting at atrial level with dilatation and tortuousness of portal vein or hepatic vein and abundant blood flow in liver. The direct signs was total pulmonary veins unconnected with left atrium, whose confluence joining into vertical vein drained right-inferiorly to portal vein or hepatic vein through diaphragm. Three parallel vessels including vertical vein, abdominal aorta and inferior vena cava arranged anteriorly, left-posteriorly and right-posteriorly with the opposite flow directions of inferior vena cava and the other two were found on sub-costal view. Sites of the drainage to the infra-diaphragm veins located portal vein in 8 patients. Stenosis of site of vertical vein connecting to portal vein or hepatic veins occurred in 3 patients.

Echocardiography has significant value in the diagnosis of pediatric ITAPVC and is capable of providing important structural and hemodynamic information for preoperative assessment of surgery. With multiple windows and multiple sections, ITAPVC could be diagnosed accurately by echocardiography. However, it is necessary to differentiate ITAPVC with intrahepatic portosystemic venous shunts or hepatic arteriovenous fistula.