Hyperpolarized 13 C magnetic resonance is a powerful tool for the study of cardiac metabolism. In this work, we have implemented protocols for the real-time hyperpolarized 13 C investigation of Langendorff-perfused rat hearts using both non-selective non-localized spectroscopy and fast spectroscopic imaging. Following [1-13 C] pyruvate infusion, we observed both catabolic and anaplerotic metabolic processes resulting in a number of metabolites, including bicarbonate, carbon dioxide, lactate, alanine and aspartate. Employing fast spectroscopic imaging, we were able to observe regional variations in pyruvate perfusion as well as in lactate and bicarbonate production.