A septal closure and port device for implantation in the atrial septum of a patient's heart includes an expandable frame with a central portion defining a lumen, and first and second opposing end portions. The frame can 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 also have 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 permits a medical instrument to be inserted through the lumen and into the left atrium, for performing a subsequent medical procedure in the left side of the heart.