Structurally supportive material is implanted or injected into cardiac veins as discrete masses at various sites in the cardiac venous system to reinforce the myocardium for the purpose of preventing, moderating, stopping or reversing negative cardiac remodeling due to various adverse cardiac conditions, both acute and chronic, or for the purpose of treating localize anomalies of the heart, or for both purposes. The sites may be arranged in a pattern about one or more chambers of the heart such that the masses cooperatively reduce stress in the chamber wall and reduce chamber size. Some patterns also cause a beneficial global reshaping of the chamber. These changes occur quickly and are sustainable, and have a rapid and sustainable therapeutic effect on cardiac function.