Abstract 16807: Role of Rotor Activation Within the Pulmonary Vein as the Driving Sources for Atrial Fibrillation: Three-dimensional Analysis using a Non-contact Mapping System

Abstract

Background: It has been suggested rotor which is located within the pulmonary vein (PV) acted as the driving sources of atrial fibrillation (AF). However, it has never been confirmed whether or not the rotor exists within PV in human. Objectives: We analyzed the activation sequence within the PV during AF and examined how the PV acted as the driving sources of AF. Methods: Selective endocardial mapping of left superior PV (LSPV) was performed during AF in 11 paroxysmal AF patients using a non-contact mapping system (EnSite 3000). Presence of rotor activation was defined when the circular activation around the functional block line once completed its whole reentrant activation. We analyzed the relation between the pivoting activation and the rotor activation. To define the preferable site of rotor and pivoting activation, we also analyzed the relation between the location of rotor and pivoting activation and region of the complex fractionated electrogram (CFE) recording site. Results: Rotor activation was observed with a mean number of 4.6±3.6 times/sec. CFE was observed at the roof (n=5), ridge (n=11) and carina (n=7) of the proximal half of LSPV with a mean area of 9.1±3.4 cm2. The number of rotor activation observed at the CFE area was significantly higher than that at the non-CFE area (4.1±3.9 vs. 0.7±1.2 times/sec, p=0.025). Total frequency of pivoting activation was 37.0±14.7 times/sec. Pivoting activation involved in the rotor activation was significantly lower than that not involved in the rotor activation (8.8±8.1 vs. 27.7±15.8 times/sec, p=0.0116). Regarding the CFE area, pivoting activation involved in the rotor activation was also significantly lower than that not involved in the rotor activation (8.4±8.2 vs. 24.1±12.0 times/sec, p=0.0105). However, there was no difference between the frequencies of pivoting activation with and without rotor activation in the non-CFE area (1.0±2.0 vs. 3.6±6.1 times/sec, p=NS). Conclusions: Rotor activation was observed at the proximal portion of the LSPV coincided with the location of CFE area. However, most of pivoting activation was not involved in the rotor activation. These suggest that AF was driven by the other meandering propagation associated with frequent non-stable pivoting activation over the CFE area.