Noninvasive Panoramic Mapping of Electrical Rotors and Comparison with Atrial Fibrosis from Magnetic Resonance Imaging in Patients with Persistent Atrial Fibrillation

Background. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can be used to evaluate characteristics of atrial fibrosis. The novel noninvasive epicardial and endocardial electrophysiology system (NEEES) allows for the identification of sources with rotor activity. This study describes a new technique to examine the relationship between rotors and LGE signal intensity in patients with persistent atrial fibrillation (PERS) scheduled for ablation.

Methods. Ten consecutive patients underwent pulmonary vein isolation for persistent atrial fibrillation. LGE CMR of both atria was performed in a 1.5-T scanner (Magnetom Avanto, Siemens, Germany). NEEES-based analysis was conducted to identify rotors using Amycard 01C EP laboratory (EP Solutions SA, Switzerland). All maps were fused using the iterative closest point algorithm and for each mapping point, the intracardiac locations were transferred onto an individual CMR-derived 3-dimensional shell. The LGE signal intensity was projected onto the anatomy from the NEEES analysis. After fusion of the rotor and LGE maps, both quantitative and qualitative comparisons were performed.

Results. NEEES analysis identified a total number of 410 electric rotors, 47.8% were located in the left atrium and 52.2% in the right atrium. CMR analysis was performed from 10 right atria and 10 left atria data sets, including 86 axial LGE CMR planes per atrium. The mean LGE burden for left atrium and right atrium was 23.9±1.6% and 15.9±1.8%, respectively. Comprehensive multivariate analysis demonstrated a lack of regional association between the extent of LGE signal intensity and the presence of rotors.

Conclusions. This is the first study demonstrating that the presence of rotors based on NEEES analysis is not directly associated with the extent and anatomic location of LGE signal intensity from CMR. Further studies evaluating the relationship between rotors and fibrosis in patients with persistent atrial fibrillation are mandatory and may inform strategies to improve ablation outcome.