Validation of Intraoperative Catheter Phase Mapping Using a Simultaneous Optical Measurement System in Rabbit Ventricular Myocardium

Background:Recently, an interoperative catheter electrode mapping system, termed ExTRa Mapping (EXT), was developed for precise diagnosis and effective treatment of non-paroxysmal atrial fibrillations (non-PAF). However, the mapping accuracy of EXT is still unclear.Methods and Results:In this study, the reliability of the EXT in comparison with that of high-resolution optical membrane potential mapping was compared. Spiral wave re-entries (SWRs) were induced in the excised rabbit hearts (n=8, 42 episodes). Electrical signals were measured by electrodes on a transparent silicone plate, with the same arrangement as in the clinical catheter, and fluorescence signals were recorded simultaneously across the plate. Based on the phase maps derived by EXT, activation patterns (one-directed propagations: 26, rotational activities: 16) were identified correctly with 95% accuracy (40/42), and the correlation coefficient of the ratio of the non-passive period was 0.95. In the rotational episodes (15), the mean position error of the centers of gravity of the SWR trajectory (2,000 ms) was 2.0 mm. For the one-directional episodes (25), the correlation coefficient of the directions of one-way propagation was 0.99.Conclusions:The phase map sequence by EXT is consistent with that by the analyses of high-resolution optical mapping. EXT is reliable for analyzing the activation pattern in the region of interest.