1987 Fiscal Year Final Research Report Summary
Optimal left ventricular loading using a realtime imprdance loading system
| Project/Area Number |
61870038
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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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 |
SUNAGAWA Kenji Kyushu Univeristy, Faculty of Mecidine, Assistant, 医学部, 助手 (50163043)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Arterial reflection / Servo-pump / Atrerial impedance / インパルス応答 |
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| Research Abstract |
We investigated hnow the pulse wave reflection in the arterial system affects ventriculat ejection. To quantitatively evaluate the effects of the pulse wave reflection on ventricular ejection, we characterized the arterial system propertied in terms of high resolution. wide band hydraulic imperance. The devived impedance spectrum was transformed to the time domain as the impulse response thorough the inverse Fourier transform (FFT). We experimentally derived the reflected wav thorough the quasi-realtime convolution of the ventriculat ejection flow with the atrerial impluse response using an isolated canine heart preparation. Similarly we simulated the ventricular ejection on the computer by convolving the ejection flow with the arterial impluse response, approximating the ventricle with a time varying elastance. Although the reflected wave considerably influenced instantaneous ventrricular pressure and arterial flow, its effect on the amount of ejection. i.e., stroke volume of cardiac output, was insignificant. As we indeicated in previous studies, the major determinant of cardiac output and external work of the left ventricle was agte asll arterial resistance at least in the normsl canine heart, Since weakineng the ventricular contranction makes the ventricular ejection sensitive to afterload, the significant effect of the reflected wave on the failing ventricel cannot be totally excluded. We clearly need further investigations.
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