Cardiac Assist by Stimulated Skeletal Muscle Cardiomyoplasty

Research Project

Project/Area Number	02670597
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Thoracic surgery
Research Institution	Hokkaido University
Principal Investigator	GOUDA Toshihiro (1991) Hokkaido University School of medicine lecturer medical hospital, 医学部・付属病院, 講師 (80186874) 酒井圭輔 (1990) 北海道大学, 医学部附属病院, 講師 (00153841)
Co-Investigator(Kenkyū-buntansha)	SAKUMA Makoto Hokkaido University School of medicine assistant medical hospital, 医学部・付属病院, 助手 (70170636) 合田俊宏北海道大学, 医学部附属病院, 助手 (80186874)
Project Period (FY)	1990 – 1991
Project Status	Completed (Fiscal Year 1991)
Budget Amount *help	¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1991: ¥600,000 (Direct Cost: ¥600,000) Fiscal Year 1990: ¥1,400,000 (Direct Cost: ¥1,400,000)
Keywords	Dynamic Cardiomyoplasty / Latissimus Dorsi Muscle Flap / Preconditioned Latissius Dorsy Muscle Flap / Drug Induced Heart Failure / 骨格筋ポンプ / 骨格筋による循環補助 / 骨格筋トレ-ニング / 心不全モデル
Research Abstract	Dynamic cardiomyoplasty involves the use of an electrically stimulated skeletal muscle wrapped around the heart to restore or augument ventricular contractility. This study was performed to evaluate the hemodynamic ability of the dynamic cardiomyoplasty useing a latissimus dorsi muscle flap (LDMF) wrapped around the ventricle. In our approach, a latissimus dorsi muscle (LDM) is disscted free from the chest wall, and is then transferred through a window made in the chest by partial removal of the second rib. At that time, the neurovascular pedicle of LDMF is careflly preserved, and two intramuscular pacing electrodes are placed in close to proximity to the course of the main nerve branches to produces diffuse stimulation of the flap. Then the LDMF is placed in contact with the epicardial surface of the heart. It is preferable to orient the muscle fibers perpendicularly to the ventricular septum, wrapping the heaet in a clockwise manner. In order to make a drug induced heart failure, propranolol inject 2-3mg, then heart rate and aortic pressure decrease about 30%. In this condition, LDMF were stimulated every 10 seconds at a burst frequency of 30Hz, synchronization to R-wave. The left ventricular pressure and aortic pressure increased 40% and 36% with LDMF stimulating. The peak aortic flow also was augumented by an average of 60% at stimulated cardiac cycles. In the future, we have to show the hemodynamic ability of the dynamic cardiomyoplasty useing a preconditioned LDMF.