The present invention is primarily directed towards an anatomically-compatible and physiologically-compatible in vivo device for improving diastolic function of either the left or right ventricle of the heart, wherein said device comprises at least one elastic component in the form of a lattice capable of being arranged in a curved conformation such that one surface of said lattice may be adapted to the curvature of the external ventricular surface of the heart, or a portion thereof, and wherein said at least one elastic component is capable of being operatively connected to the external ventricular surface of the heart by means of one or more connecting elements.
