| Project/Area Number |
15500349
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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 |
Medical systems
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| Research Institution | Tokyo Women's Medical University School of Medicine |
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Principal Investigator |
ISHIZUKA Naoko Tokyo Women's Medical University, School of Medicine Dept.of Cardiovascular Sciences, Lecturer, 医学部, 講師 (30159751)
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| Co-Investigator(Kenkyū-buntansha) |
NIKI Kiyomi Tokyo Women's Medical University, School of Medicine Dept.of Cardiovascular Sciences, Associate Professor, 医学部, 助教授 (40218095)
SUGAWARA Motoaki Tokyo Women's Medical University, School of Medicine Dept.of Cardiovascular Sciences, Professor, 医学部, 教授 (60010914)
CHANG Dehua Tokyo Women's Medical University, School of Medicine Dept.of Cardiovascular Sciences, Assistant, 医学部, 助手 (10343550)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Ultrasonic diagnosis / Heart failure / wave intensity / carotid artery / Dilated cardiomyopathy / Hypertrophic cardiomyopathy / Cardiac function / Doppler echo / ドプラー心エコー |
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| Research Abstract |
Wave intensity (WI) 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. Arterial wave intensity in normal subjects has two positive sharp peaks. The first peak occurs during early systole, the magnitude of which increases markedly with increases in cardiac contractility. The second peak, which occurs towards the end of ejection, decreases with increases in the time constant of left ventricular isovolumic relaxation. We developed an ultrasonic on-line system of measuring WI, and applied it to pathophysiological analysis of failing heart. The system is composed of a computer, a WI unit and an Aloka ProSound SSD-6500 ultrasonic machine (Aloka, Tokyo) equipped with a combined tissue imaging (10 or 13 MHz) and Doppler (5 MHz) transducer. We applied this system to the carotid artery in patients with dilated cardiomyopathy (DCM).
We classified patients with DCM as either having had the first episode of heart failure at an age less than 40 (group Y) or at the age of 40 or greater (group E). Applying wave intensity, we studied whether there are any differences in left ventricular ejection mode between the two groups. In group Y, there were patients who had normal first peak in spite of the fact that they showed marked dilatation and deterioration of contractility of the heart echocardiographically. In such cases, arterial stiffness was lower, and blood velocity was higher. In group E, arterial stiffness was higher and the first peak of WI was lower. Arterial stiffness is an afterload for the ventricle. For manifestation of DCM, ventriculo-arterial interaction is an important factor. Wave intensity is useful for analyzing ventriculo-arterial interaction.
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