1987 Fiscal Year Final Research Report Summary
Relationship between Coronary Circulation and Myocardial Function in the Right Heart
| Project/Area Number |
61570423
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KOYANAGI Samon Kyushu University, Faculty of Medicine, Lecturer, 医学部, 講師 (90128017)
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| Co-Investigator(Kenkyū-buntansha) |
TAIRA Yuji Kyushu University, Faculty of Medicine, Assistant, 医学部, 助手 (70179399)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Myocardial Function / Coronary Circulation / Coronary Autoregulation / 右室肥大 |
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| Research Abstract |
The relationship between coronary perfusion pressure and regional myocardial performance of the right ventricular free wall was studied,in the presence or absence of right ventricular hypertemsion in 13 open-chest dogs.The right coronary artery was perfused through a shunt from a carotid artery.Regional systolic shortening of the right ventricular free wall was measured by means of a sonomicrometric technique at various levels of coronary perfusion pressure.Regional shortening was insensitive to coronary perfusion pressure or flow when it was above 31 mm Hg or 0.27 ml/min per g.Once coronary perfusion was below this critical level, regional shortening in both base to apex and circumferential orientations decreased linearly, depending on the degree of perfusion pressure. Despite the presence of a monoexponential relationship between coronary perfusion pressure or flow and regional shortening, a direct linear relation between perfusion pressure and flow was consistently noted,with or without pulmonary artery banding,suggesting that there is limited autoregulation of right coronary flow.The critical perfusion pressure for maintaining regional myocardial function of the right ventricle was highly dependent on the level of right ventricular systolic pressure (r=0.64-0.72,P<0.05).Thus,right ventricular systolic pressure was one of the important determinants of regional wall motion during coronary underperfusion.
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