Fig. 1

Transthoracic echocardiographic views (a and d) to detect and measure right superior (RSPV, [b]) and inferior (RIPV, [c]) and left superior (LSPV, [e]) and inferior (LIPV, [f]) pulmonary veins. The RSPV and RIPV can be visualised in apical 4-chamber or 5-chamber or between these two classical views (a). The LSPV adjoins to the left atrial appendage and the LIPV to descending aorta in the adjusted parasternal short-axis aortic view (d). Right and left ventricles (RV and LV) and atria (RA and LA), aorta (AO) and pulmonary artery (PA) are marked as references in the views. The diagrams in panels (a and d) were drawn by W-Y.Y. and the echocardiographic images in Panels (b, c, e and f) were recorded by Q-Q.D.