Research Aiming at the Development of Cardiac Resynchronization Therapy for Single Ventricles: Elucidation of the Conduction System Using Phase-Contrast X-ray CT

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K08818
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 55030:Cardiovascular surgery-related
• Research Institution: Niigata University
• Principal Investigator: Shuichi Shiraishi 新潟大学, 医歯学系, 准教授 (00422600)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 単心室 / 位相差X線CT / 刺激伝導系 / 心臓再同期療法

Outline of Final Research Achievements

We examined five human heart specimens with tricuspid atresia using phase-contrast X-ray CT with synchrotron radiation and created three-dimensional models for analysis. The median distance to the mitral valve annulus was 2.0 mm. In four autopsied hearts with normal great vessel relationships, the AV conduction axis was located below the commissure between the left and non-coronary cusps of the aortic valve, extending to the nadir of the non-coronary cusp.

There was a negative correlation between 3D EF and BNP, and the 3D EF in ccTGA was lower than that in the normal control group. It is necessary to adjust the lead position to support three-dimensional pacing. Pacing of the dorsal part of the right ventricular inflow tract and the anterior part of the right ventricular outflow tract, covering the right ventricle in both the longitudinal and anteroposterior directions, was effective.

Free Research Field

心臓血管外科

Academic Significance and Societal Importance of the Research Achievements

これまで詳細が不明であった三尖弁閉鎖をはじめとした単心室疾患群の刺激伝導系が位相差X線CTにより詳細に描出され、3次元構築したモデルが作成されたことにより心臓再同期療法への可能性が広がっただけでなく、大動脈弁輪拡大術式の選択にも応用が可能となる。
開胸手術の際の心外膜電極の位置変更による心室壁運動の変化が組織ドップラー法などにより詳細に観察されたことにより、単心室疾患群へのより有効な心臓再同期療法が行い得る。