Basic and clinical researches on heart rate variability, endothelial function, circadian variation of blood pressure and their relationships
| Project/Area Number |
11670698
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Circulatory organs internal medicine
|
|---|
| Research Institution | Nagoya City University |
|---|
Principal Investigator |
HAYANO Junichiro Nagoya City University Medical School, Associate Professor, 医学部, 助教授 (90173054)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAMADA Akira Nagoya City University Medical School, Research Associate, 医学部, 助手 (30230444)
TAKESHIMA Nobuo Nagoya City University Medical School, Associate Professor, 自然科学研究教育センター, 助教授 (00137126)
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
|
|---|
| Keywords | heart rate variability / baroreflex sensitivity / endothelial function / NO / exercise therapy / autonomic nervous system / atrial fibrillation / mortality / 左受容器感受性 / 心房組動 / 生活習慣病 / 血管内皮機能 / 概日リズム / 非線形解析 |
|---|
| Research Abstract |
In this project, we investigated the relationships among variability and nonlinear dynamics of heart rate, endothelial function and circadian variation of blood pressure in various physiological and clinical conditions. The major findings are as follows :
(1) Chronic inhibition of NO synthesis by administration of N(G)-nitro-L-arginine methyl ester lead sustained hypertension and bradycardia in freely moving canines. In this condition, despite that heart rate variability assessed as standard deviation of 24-h R-R interval was increased, complexity of heart rate asses as spectral exponent of 1/f fluctuation was reduced. These indicate that variability and complexity of heart rate fluctuation show differential responses to chronic inhibition of NO synthesis and that circulatory regulation by NO may be involved in the genesis of complexity but not variability of heart rate.
(2) In patients with chronic atrial fibrillation who were followed-up for 33 months, decreased irregularity of R-R int
… More
erval assessed as approximate entropy predicted an increased risk for cardiac death, but not for fatal stroke. Although atrial fibrillation was an exclusion criteria in earlier studies of heart rate variability, nonlinear dynamics of heart rate includes prognostic information even in this condition.
(3) Well-rounded exercise training performed for 12 weeks in normotensive and mild-hypertensive elderly subjects decreased daytime blood pressure only in subjects who showed nocturnal blood pressure decline (dippers) ; however, the training did not change either daytime or nighttime blood pressure in nondipper normotensive or hypertensive subjects. Consequently, the type of circadian variation of blood pressure was unchanged by the training in any group. On the other hand, the endothelial function assessed as flow-mediated vasodilation response was reduced only in non-dipper hypertensive subjects at baseline and, only in this group, the training improved the endothelial function. Heart rate variability was unchanged by the exercise training. Less
|
Report
(3 results)
Research Products
(13 results)
