 Patients will be followed for one year at 3, 6, and 12 months. Data collected will evaluate change in pacing thresholds over time as well as cardiac troponin I, creatinine kinase MB function, and myoglobin levels within the first 12 hours following the scans, side effects, symptoms, the need to make pacemaker program changes, and possible artifacts created by the pacemaker on the MRI scan. 