Respiratory motion in cardiovascular MRI presents a challenging problem with many solutions. Current approaches require breath-holds, neglect through-plane motion or significantly increase scan time. Our patient-specific prospective motion correction strategy addresses these issues and corrects for respiratory motion in real time. Numerous cardiac imaging applications stand to benefit from our approach, including perfusion imaging, parameter mapping, and late gadolinium enhancement. By modeling on a patient-specific basis, and prospectively correcting for respiratory motion, we expect to significantly improve the reliability and efficiency of CMR. For demonstration, the proposed strategy was applied to improve the accuracy of free-breathing T1 and T2 mapping.