Systems, methods and devices are provided for improving the hemodynamic efficiency of a patient's heart by implanting one or more reinforcement elements on or with the heart and providing electrical stimulation to the heart. The reinforcement elements may include magnetic and/or shape memory material and are configured to reshape the heart so as to boost the heart's mechanical energy during a response to the electrical stimulation. In some embodiments, at least one reinforcement element includes an electrode configured to sense electrocardiogram signals within the heart. An electrical stimulation device such as an implantable or external pacemaker/defibrillator may be configured to control delivery of electrical pulses to the heart based on the sensed electrocardiogram signals. In addition, or in other embodiments, at least one reinforcement element includes an electrode configured to deliver the electrical pulses to the heart.