Integration of MRI in evaluation and ablation of atrial fibrillation

Magnetic resonance imaging (MRI) based approaches are supporting rapid advances in all phases of the management of atrial fibrillation (AF) patients, especially with the use of contrast agents and novel MRI acquisition techniques. In this report, we summarize briefly some recent advances in our use of MRI for AF management with special focus on the impact of these findings on the modeling and simulation of AF. We summarize results from two clinical studies, one of patients before radio frequency ablation of atrial fibrillation and one after ablation. In pre-ablation patients, significant extent of enhancements in delayed enhancement MRI of the left atrium is predictive of worsened outcome from ablation. The presumed mechanism is the presence of fibrosis in the posterior wall of the left atrium and supports the known finding that patients in chronic atrial fibrillation develop elevated levels of fibrosis. The implications of this finding on modeling of atrial electrical activity are that any such models must include both structural and functional fibrosis if they are to reflect realistic conditions.