The sinus venosus atrial septal defect (“ASD”) treatment device includes has a generally tubular or funnel shaped configuration. A first end of the device can have a diameter that is less than a diameter of a second end of the device. The device can be inserted in the right upper right pulmonary vein PV. The second end of the device is configured to expand in a skirt-like configuration once the device is positioned in the right upper right pulmonary vein PV. In this manner, the device closes the upper sinus venosus hole and diverts anomalous pulmonary venous drainage into the left atrium.