[The limitation of transthoracic echocardiography in diagnosing partial anomalous pulmonary venous drainage].

Objective: To improve the diagnostic accuracy of transthoracic echocardiography (TTE) by analyzing its limitations in diagnosing partial anomalous pulmonary venous drainage (PAPVD). Method: This was a retrospective analysis of PAPVD patients seen at the Children's Hospital of Fudan University from October 1 2006 to October 1 2016. The echocardiographic data were compared to findings on multi-slice spiral CT (MSCT), cardiac catheterization or surgery. The echocardiography machines used were Philip IE33, GE Vivid 7 and Vivid i with frequency ranging from 5.0 MHz to 7.5 MHz. The cardiac structure was analyzed according to Van Praagh segments. Result: A total of 43 cases of PAPVD were enrolled, male∶ female ratio 20∶23 with average age (27.9±21.4) months. Among them, 3 cases were simple PAPVD and 40 cases had other associated congenital heart diseases. TTE was successful in diagnosing 29 cases (67%) while 14 cases were missed. The diagnostic rate for right pulmonary vein drainage into superior vena cava, right atrium, inferior vena cava were 5/10, 17/20, and 3/5 respectively while left pulmonary vein drainage into left innominate vein was only 1/4. Added TTE images to re-exam the 9 of the 14 missed cases, 5 cases of abnormal drainage from right superior pulmonary vein were diagnosed, while 4 cases of drainage from right lower or left pulmonary vein were only picked up by indirect signs. Conclusion: The distance of the pulmonary veins from the routine ultrasound view and the possibility of branch number variation may limit the accuracy of TTE in diagnosing PAPVD, especially for drainage from right lower and left pulmonary vein. But TTE is still the preferred diagnostic method. The diagnostic rate could be increased by paying special attention to non-routine views including the suprasternal fossa, the right parasternal and subcostal area.