Fig. 1
From: Mixed type of total anomalous pulmonary venous connection: diagnosis, surgical approach and outcomes
a to f are the illustrations of the first to the sixth classification system.the pulmonary vein drainage in the illustrations (RPV or LPV) is variable, the pulmonary venous drainage sites such as CS,RA and SVC are the key points. CS: Coronary sinus;C: Confluence;VV:vertical vein;IVC: inferior vena cava;SVC: the superior vena cava;RA: Right atrium; LPV, left pulmonary vein; RPV, right pulmonary vein; BV, brachiocephalic vein