Abstract 3372: Mechanisms of Complex Fractionated Atrial Electrograms (CFAE)
Background: Complex fractionated atrial electrograms (CFAE) have been suggested as an important site for ablating atrial fibrillation. The etiology and the mechanism of these signals have not been completely elucidated due to the limitations in the spatial resolution of the mapping tools and the interpretation of these signals in relation to simultaneously acquired signals in the neighboring atrial tissue.
Objective: We tested the hypothesis that CFAE occurs during atrial fibrillation either when the core of rotor meanders or at the boundary of a wave break.
Methods: In order to test the hypothesis we performed our analysis using: (i) optically mapped atrial monolayers and (ii) clinical ventricular fibrillation (VF) data from 3 intra-operative studies. The optically mapped monolayers were from the rat atrial myocytes using Di-4-ANEPPS and a CMOS Brainvision Ultima camera system. The image sequences were analyzed and a previously published method of obtaining pseudo unipolar electrograms by spatial integration of fluorescence signals was used to derive the bipoles. The derived pseudo bipolar electrograms were used to detect the CFAE in testing the proposed hypothesis. The proposed hypothesis was then verified using the clinical VF data acquired from 3 intra-operative patients using a 672-channel data acquisition system.
Results: Three monolayer experiments were performed by placing the pseudo electrodes at: (a) various locations in and around the core of a stable rotor, (b) the locations of wave break, and (c) predefined pathways simulating a meandering rotor. We observed CFAE in the derived pseudo bipolar electrograms for (b) and (c) while no CFAE was observed for (a). As a validation procedure for the above findings, we analyzed bipolar electrograms of 3 intra-operative patients where VF episodes were mapped. The analysis confirmed our findings on the occurrence of complex fractionated electrograms in the wave break and meandering rotor situations. The stable rotor situation could not be verified as in real world patient data it is rare to observe stable rotors.
Conclusion: The core of a meandering rotor and wave breaks may provide a mechanism for fractionated bipolar electrograms in fibrillation.