MORPHOLOGICAL FEATURES OF THE LEVOATRIOCARDINAL (OR PULMONARY-TO-SYSTEMIC COLLATERAL) VEIN

Three cases with an anomalous pulmonary-to-systemic collateral vein (l evoatriocardinal vein) connecting the left atrium or one of the pulmon ary veins to a systemic vein are described. In two of these cases the atrial septum is intact, tile left atrioventricular connection is abse nt (mitral atresia), and the anomalous vein is the escape channel for pulmonary venous return. In the remaining case, a muscular membrane di vides the left atrium, separating the pulmonary venous component from the distal component. The collateral vein may be mistaken for the vert ical vein that is associated with totally anomalous pulmonary venous c onnections, but in all our cases the pulmonary veins inserted normally into the left atrium. Cross-sectional echocardiography, including con ventional and color flow Doppler mapping, should overcome potential di fficulties in diagnosis.