| Project/Area Number |
12670698
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | TOHO UNIVERSITY |
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Principal Investigator |
YAMAGUCHI Tetsu MEDICINE, TOHO UNIVERSITY, PROFESSOR, 医学部, 教授 (30010416)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAZAWA Kazuo NATIONAL CARDIOVASCULARCENTER RESEARCH INSTITUTE EPIDEMIOLOGY, RESEARCHER, 研究員 (50198058)
IKEDA Takanori MEDICINE, TOHO UNIVERSITY, INSTRUCTOR, 医学部, 助手 (80256734)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | VENTRICULAR FIBRILLATION / REENRY / MAPPING / COMPUTER SIMULATION / WAVE PROPAGATION / TISSUE STRUCTURE / コンピューターシミュレーション |
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| Research Abstract |
It is unclear how the patterns of wavelet propagation during ventricular fibrillation (VF) vary between structurally different tissues. We hypothesized that the structural complexities of the septal tissue influence the maintenance of reentrant wavelets in the ventricle.
Methods and Results : Endocardial activation patterns during VF were analyzed in the isolated, per fused canine right ventricular (RV) free wall (n=9), interventricular septum (n=5), and left ventricular (LV) free wall (n=6) using a computerized mapping system (2-mm resolution) with 120-ms consecutive windows. Each tissue sample was cut progressively to reduce the tissue mass until the VF was terminated. More wavelets were seen in the septa than in the RV and LV free walls at baseline (P=0.004), and VF in the septa displayed a shorter cycle length than in the RV and LV free walls (P=0.017). As the tissue mass decreased, VF became successively more organized in all regions : the number of wavelets decreased and the cycle length of VF lengthened. Single and "figure-eight" stationary, reentrant wavelets were often mapped after tissue mass reduction in the RV free walls and rarely in the LV free walls, but they were not observed in the septa. Less critical mass was required to maintain VF in the septa than in the RV and LV free walls (P=0.0006). Gross anatomic and histologic examinations indicated that the tissue structure of the septa is more complex than that of the RV and LV free walls.
Conclusion : VF activation patterns with progressive reduction of tissue mass differ for the septum and the ventricular free walls. The structural complexities of the septal tissue influence the maintenance of fibrillation in the ventricle.
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