1998 Fiscal Year Final Research Report Summary
A new index for analysing ventriculo-arterial interactions : development of wave intensity
| Project/Area Number |
09680866
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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 |
Biomedical engineering/Biological material science
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| Research Institution | Tokyo Women's Medical University. |
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Principal Investigator |
NIKI Kiyomi Tokyo Women's Medical University, Faculty of Medicine, Research Fellow, 医学部, 助手 (40218095)
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| Co-Investigator(Kenkyū-buntansha) |
SUGAWARA Motoaki Tokyo Women's Medical University, Faculty of Medicine, Professor, 医学部, 教授 (60010914)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Wave Intensity / cardiac contractility / expansionwave / combined Doppler and echo-tracking system / centriculo-arterial interactions / コンプライアンス / 脈波速度 |
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| Research Abstract |
Wave intensity is a new index for evaluating ventriculo-arterial interactions. Wave intensity is defined as (dP/dt)(dU/dt) at any site of the circulation, where dP/dt and dU/dt are the time derivatives of blood pressure and velocity, respectively. A positive value of wave intensity indicates that the effects of pressure waves traveling from the heart towards the periphery are predominant in the formation of pressure and velocity waveforms at the measuring site, while a negative value indicates that the effects of waves reflected from the periphery predominate. Arterial wave intensity in normal subjects have two positive sharp peaks. The first peak occurs during early systole when a forward-travelling compression wave is generated by the left ventricle. The magnitude of this peak increases markedly with the increase in cardiac contractility. The second peak, which occurs towards the end of systole, is caused by generation of a forward-travelling expansionwave.
We obtained the carotid arterial wave intensity noninvasively. Using a combined Doppler and echo-tracking system, we simultaneously measured carotid arterial diameter and blood flow velocity. Since arterial pressure waveforms and diameter change waveforms are similar, we obtained a blood pressure waveform, noninvasively, by measuring the diameter and calibrating its peak and bottom values by systolic and diastolic blood pressure, measured with a cuff-type manometer. We examined characteristics of wave intensity in patients with various heart disease.
The pattern of wave intensity varies considerably with the type heart disease. Wave intensity is useful for analysing ventriculo-arterial interaction in patients with heart disease.
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