Incompetency or regurgitation of a cardiac valve is treated by injecting a space occupying material or implanting a space occupying device within a papillary muscle or in heart tissue near a papillary muscle to cause lengthening or repositioning of the papillary muscle in a manner that improves coaptation of the valve leaflets and lessens valvular incompetency or regurgitation. The procedure may be performed by open thoracotomy, thoracoscopically, by a tran-endocardial catheter based approach or by a trans-coronary catheter based approach.