Disclosed are devices and methods for treating regurgitation through a valve in the heart. The devices can include an expandable, fluid-tight bladder configured to be deployed between valve leaflets of the heart valve. The bladder can include an upper portion that extends into the atrium of the heart； a lower portion that extends into the ventricle of the heart； and a middle portion positionable within the line of valve leaflet coaptation that provides a sealing surface for one or more of the leaflets.
