Utah Classification of Atrial Fibrillation
Our research at the University of Utah uses 3D delayed-enhancement magnetic resonance imaging (DE-MRI) to determine the degree of fibrosis in the left atrial myocardial tissue of AF patients before radiofrequency ablation. We developed protocols and pulse sequences to optimize the images.
Patients are classified in one of four categories based on percent of fibrosis, quantified with delayed enhancement MRI (DE-MRI), relative to the left atrium (LA) wall volume: Utah Stage 1 (minimal); Utah Stage 2 (mild); Utah Stage 3 (moderate); and Utah Stage 4 (extensive).
The results of multiple studies indicate that the Utah Staging System (based on left atrial enhancement) can be used to personalize the management of AF. This model can be used to better define candidates for ablation, predict long-term prognoses and, in the future, perhaps assess risks for strokes and heart failure. This staging system also can be beneficial in planning a corresponding ablation strategy and anticoagulation management based on an increase in the predictive statistics of the CHADS2, a clinical prediction rule for estimating the risk of stroke.
In addition, the use of late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) allows for ablation lesion characterization, a tool that was proven helpful in identifying sites of lesion recovery after ablation procedures. Identifying these recovery sites is not only crucial in ensuring ablation success, but also in selecting appropriate re-ablation candidates in case arrhythmias recur.
Three-dimensional, high-resolution imaging has tremendous potential in Atrial Fibrillation diagnosis and treatment, and researchers are collaborating worldwide to develop new techniques for improving clinical outcomes.