3D LGE is used to assess scar in patients with atrial fibrillation. However, the fast and variable heart rate in these patients results in poor image quality. An existing dynamic-TI method varies inversion time on a beat-by-beat basis (according to the previous cardiac cycle length) to improve myocardial nulling, but blood signal variations are incompletely corrected and cause ghosting. We have developed an improved technique which bases the beat-by-beat TI on the history of RR intervals (rather than the previous one) and reduces blood signal variations while maintaining myocardial nulling. Simulations with patient RR interval distributions show significantly improved results.