Abstract 2711: Analysis of the Mechanisms Initiating Random Wave Propagation at the Onset of Atrial Fibrillation Using the Non-contact Mapping System: Role of Complex Fractionated Electrogram Region
Background: The precise mechanisms initiating random reentry in atrial fibrillation (AF) has not been well clarified.
Objectives: The purpose of this study was to examine the mechanisms of the initiation of random wave propagation at the onset of AF. Furthermore, we evaluated the role of complex fractionated atrial electrograms (CFAE) region in the initiation of AF.
Methods: Endocardial mapping of the left atrium was performed at the spontaneous onset of AF using a three-dimensional non-contact mapping system (EnSite 3000) in 10 patients with paroxysmal AF. We analyzed how the meandering reentrant wave which maintains the AF was initiated, especially in relation to the CFAE region.
Results: Sixteen spontaneous AF onset episodes were observed. All AF episodes were initiated by the focal repetitive discharges, derived from pulmonary vein (PV) (n = 10) and from non-PV CFAE region (n = 6), but not from the non-CFAE region. During AF, CFAE were observed in the roof (10 pts), septum (9pts), anterior (5pts), posterior (3pts), left atrail appendage (7 pts) and PV region (11 pts), respectively. The mean area of CFAE region was 13.3±5.4 cm2. Following the repetitive focal discharges, there were 2 types of initiation of meandering wave propagation; 1) Focal discharge propagated slowly into the CFAE region accompanied by the localized conduction block in the CFAE region. Then, the wave exit to the non-CFAE region and reentered the CFAE region from the previous localized block region (6 episodes), 2) Focal discharge propagated slowly into the CFAE region accompanied by the localized functional conduction block in the CFAE region. Then, the wave anchored around the localized conduction block line, resulted in the pivoting activation in the CFAE region (10 episodes). After the appearance of these meandering wave propagation over CFAE region, random reentrant wave propagation started subsequently in all patients.
Conclusions: Localized functional conduction block and slow propagation in the CFAE region, following the repetitive focal excitation from PV and CFAE, initiate the meandering wave propagation, leading to the outbreak of random reentrant wave propagation. The CFAE region plays a crucial role for the initiation of AF.