A septal closure and port device for implantation in the atrial septum of a patient's heart comprises an expandable frame can comprise a central portion defining a lumen, and first and second opposing end portions. The frame is configured to expand and contract between a compressed, tubular configuration for delivery through the patient's vasculature and an expanded configuration in which the first and second end portions extend radially outwardly from the opposite ends of the central portion. The device can further comprise a valve member supported on the frame and positioned to block at least the flow of blood from the left atrium to the right atrium through the lumen of the frame. The valve member is configured to permit a medical instrument inserted through the lumen and into the left atrium, such as for performing a subsequent medical procedure in the left side of the heart.