The present invention is directed to an apparatus for endovascularly replacing a patient's heart valve, the apparatus comprising an expandable anchor supporting a replacement valve and a delivery catheter adapted to deliver the anchor and replacement valve to a vicinity of the heart. The anchor and replacement valve are adapted for percutaneous delivery and deployment to replace the patient's heart valve. The anchor and the replacement valve are further adapted to permit blood flow through the replacement valve and to prevent blood backflow through the replacement valve after the replacement valve exits the catheter and before final deployment of the anchor.
