A method of treating diastolic heart failure includes implanting a cardiac implant in a heart of a subject diagnosed as suffering from diastolic heart failure. A superior portion of a flexible tether of the cardiac implant is anchored to one or more left-atrial sites of one or more walls of the left atrium. An inferior portion of the flexible tether is anchored to a site of a wall of a mid third of the left ventricle, of a wall of an apical third of the left ventricle, and/or of a papillary muscle of the left ventricle. As a result, the flexible tether reduces a volume of the left atrium during at least a portion of ventricular diastole of each cardiac cycle, thereby enhancing ventricular filling. Other embodiments are also described.