A method for improving function of a cardiac valve in a patient, the cardiac valve having at least one leaflet that is attached to a papillary muscle: Inserting a balloon, that is in a first uninflated condition and having a first diameter, within tissue that is part of to the papillary muscle, and thereby separating tissue that was previously connected together, by a maximum amount equal to the first diameter; inflating the balloon to a second inflated condition having a second diameter greater than the first diameter, thereby permanently stretching tissue in the papillary muscle and separating the tissue from the first diameter to a maximum amount equal to the second diameter; deflating the balloon to the first uninflated condition, and thereby returning the tissue to a separation of a maximum amount substantially equal to the first diameter; and then removing the balloon from the patient.