Electrophysiological mechanism of atrial fibrillation

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K15906
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53020:Cardiology-related
• Research Institution: Nihon University
• Principal Investigator: NAGASHIMA Koichi 日本大学, 医学部, 准教授 (90753989)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: 心房細動 / カオス解析 / 自己相関関数 / フラクタル次元

Outline of Final Research Achievements

Atrial fibrillation (AF) mechanism has not been elucidated. We quantified the chaotic characteristics of AF using the local electrograms (EGMs). 65 AF cases underwent pulmonary vein isolation (PVI). The bipolar EGMs during AF of the 4 PVs and 3 sites of the left atrial (LA) body were recorded for 20 seconds before the PVI. AF was no longer sustained in 34 cases (group 1) and still sustained in 31 (group 2, n=31) after PVI. With the EGMs, chaos analyses including autocorrelation function (ACF) plots and the fractal dimension (FD) were performed. Group 1 more frequently showed regular ACF plots in the left superior and inferior PVs than group 2, suggestive of more organized PV activities in group 1. The FD values of LA body were lower in group 1 than group 2, suggesting less chaotic activity of LA body in group 1. The mean FD in 4PVs and LA body were correlated with LA volume. Regular ACF plots might reflect the focal AF driver, and the FD might indicate the LA remodeling.

Free Research Field

不整脈

Academic Significance and Societal Importance of the Research Achievements

AFが根治する群でのPV電位において、周期的なACFを示す頻度が高かったことから、ACFはAFの原因となっている高頻度興奮部位の特定に有効である可能性がある。PVIによってAFの根治しない患者において、肺静脈以外にも高頻度興奮部位があることが報告されている。そのような患者に対し、高頻度興奮部位の特定にACFは有用となる可能性がある。また、FDによりLAリモデリングの定量評価が可能と考えられる。そのため、PVI後の追加アブレーションの必要性の有無や、抗不整脈による後療法の選択にも有用な可能性がある。