心筋異方向性伝導と心室性不整脈発生機序に関する高密度マッピング法を用いた研究

高密度图谱法研究心肌各向异性传导及室性心律失常机制

• 批准号: 07770496
• 负责人: 臼田 和生
• 金额: $ 0.64万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Encouragement of Young Scientists (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07770496/
• 关键词: 心室性不整脈; 異方向性伝導; 心筋虚血; 心表面マッピング

【目的】心筋組織は心筋線維の配列方向によって興奮伝導速度が異なる異方向性伝導特性を有し,摘出心筋を用いた検討などから,心筋構築の異方向性がリエントリ-性不整脈発生機構に関与する可能性が指摘されているが,未だ十分に解明されてはいない.本研究では,イヌ生体拍動心に高密度マッピング法を用いて急性心筋虚血時における心筋異方向性伝導と心室性不整脈発生の関係を解明することを目的とした.【方法】雑種成熟イヌ8頭(8〜12kg)をpentobarbitalで麻酔後,人工呼吸下で開胸し,心膜を切開して心臓を露出し,左冠状動脈前下行枝(LAD)潅流領域にマッピング電極を留置した.マッピングには極間1mmの双極金球電極96対を1.5mm間隔に8列×12行に配列し,中央に記録用電極とは別に刺激用双極電極を1対配したマット電極を用いた.Base lineの記録終了後LADを近位部で結紮し,経時的に中央刺激電極で基本刺激周期300msの刺激を行い興奮伝播過程を記録した.興奮伝播様式の記録解析にはHPM-7100(フクダ電子社)を用いた.【結果】Base lineにおける心表面心筋線維の長軸方向興奮伝播速度(以下θL)は,θL=0.705±0.067m/s,短軸方向興奮伝播速度(以下θT)は,θT=0.344±0.057m/sであった.LAD結紮5〜10分後には,θL=0.472±0.123m/s,θT=0.255±0.038m/sといずれも有意に低下した.結紮20〜30分後θL=0.561±0.128m/sと長軸方向の興奮伝播速度が一時改善したが,結紮40〜50分後には再び興奮伝播速度の低下が認められた(θL=0.441±0.112m/s,θT=0.253±0.073m/s).【総括】イヌ急性心筋虚血モデルにおいて,心表面異方向性伝導の経時的な変化率に差がみられ,この過程が急性心筋虚血時の不整脈発生機序と関連する可能性が示唆された.

[Objective] To investigate the different directivity of the tendon structure in different directions of the arrangement of the tendon linear dimensions, and to investigate the possible relationship between the different directivity of the tendon structure and the generation mechanism. The purpose of this study is to use a high-density computer array method to investigate the relationship between the anisotropic conduction of cardiac tendons and the onset of ventricular arrhythmia during acute cardiac tendon deficiency. [Method] Eight adult rabbits (8 ~ 12kg) were anesthetized, and the heart membrane was opened under artificial respiration. The left coronary artery anterior descending branch (LAD) flow field was reserved. Bipolar gold ball electrodes 96 pairs of electrodes 1mm apart from each other are arranged in 8 rows ×12 rows at intervals of 1.5 mm, recording electrodes at the center and stimulation bipolar electrodes at the center are arranged in 1 pair. HPM-7100(FK Electronic News Agency) is used in the analysis of excitation propagation patterns and records. [Results] The excitation propagation velocity (θL) in the long axis direction (θL=0.705±0.067m/s) and the excitation propagation velocity (θT) in the short axis direction (θ T=0.344±0.057m/s) of the Base line were reversed. The excitation propagation velocity (θL=0.472±0.123m/s,θT=0.255±0.038m/s) decreased intentionally after LAD ligation for 5 ~ 10 minutes. After ligation for 20 ~ 30 min, θL=0.561± 0.128 m/s, the excitation propagation velocity in the long axis direction improved temporarily, and after ligation for 40 ~ 50 min, the excitation propagation velocity decreased again (θL=0.441± 0.112 m/s,θT=0.253± 0.073 m/s). In summary, the rate of change of cardiac surface anisotropic conduction during acute cardiac insufficiency is different, and the possibility of correlation between this process and the irregular pulse development sequence during acute cardiac insufficiency is shown.