MECHANICS OF LV SUCTION AND DIASTOLIC FILLING

左心室吸力和舒张期充盈的机制

基本信息

批准号：
2224928
负责人：
NEIL B INGELS
金额：
$ 23.94万
依托单位：
PALO ALTO MEDICAL FOUNDATION RES INST
依托单位国家：
美国
项目类别：
财政年份：
1992
资助国家：
美国
起止时间：
1992-08-12 至 1998-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2224928
关键词：
bioenergetics cineradiography computer graphics /printing congestive heart failure dogs elasticity fluoroscopy heart motion heart ventricle intracardiac pressure mechanical pressure mitral valve ventricular hypertrophy

项目摘要

To date, the mechanism underlying ventricular suction is unknown, and its role in maintaining physiological diastolic function is unproven. Ventricular suction is thought to play an important role in the almost explosive character of the early, rapid filling phase of the cardiac cycle (when much of ventricular inflow occurs); to contribute greatly to the diastolic filling necessary for efficient operation of the heart at rapid heart rates and with exercise; and to increase the overall efficiency of the heart by applying part of the mechanical energy of systole to power diastole. A failure of ventricular suction has been implicated in the excessively high left atrial pressures in the failing heart. The long range goal of the work described in this application is to determine the mechanical and structural basis for ventricular suction and elucidate the importance of diastolic suction to left ventricular filling under both physiological and pathophysiological conditions. This goal is now attainable due to three recent advances in our laboratories: First, the ability to acquire, by automated computerized analysis of stereo videoradiograms of implanted radiopaque markers, hundreds of simultaneous three-dimensional strains throughout the entire left ventricular myocardium; Second, a new experimental technique for left atrial pressure clamping and left ventricular volume clamping (servo-controlled) which shows promise in preliminary tests of revealing, for the first time, the mechanical correlates of left ventricular suction; and Third, a new computer graphics approach to visualization of large numbers of simultaneous instantaneous regional strains and shears allowing recognition of patterns, both spatial and temporal, not otherwise recognizable in the myriad of data arising from studies such as these. The proposed studies address the following questions: (1) What is the range of suction pressures which can be developed in the presence of a normal mitral valvular apparatus? (2) What is the importance of the contribution of suction to left ventricular filling? (3) Is elastic energy stored in myocardial torsional deformation, transmural compression, in-plane strains, or combinations of these shears and strains? (4) What are the regional distributions of elastic recoil and the sequence of regional energy release during diastole and how do these influence gradients of pressure within the LV? (5) What fraction of total LV filling can be accounted for by the mitral valve engulfing blood as it recoils toward the left atrium? (6) What are the effects of the pathophysiological conditions accompanying (a) volume overload hypertrophy and (b) pressure overload hypertrophy on regional diastolic mechanics, the storage of elastic energy during systole and its release during diastole, and the capability of the LV to develop suction? and (7) In what sequence and what proportion is energy stored in and released from the connective tissue matrix and the myocytes to aid filling? The answers to these questions should provide important new information regarding these fundamental aspects of diastolic function.

迄今为止，心室吸力的基础机制尚不清楚，并且维持生理舒张功能的作用未经证实。人们认为心室吸力几乎在心脏早期，快速充满阶段的爆炸性循环（发生大部分心室流入时）；为大力做出贡献心脏有效操作所必需的舒张期填充快速心率和运动；并增加整体通过应用部分机械能的机械能的效率收缩到舒张动力。心室吸力的失败已经涉及到过高的左心压力心。本应用程序中描述的工作的远距离目标是确定心室吸力的机械和结构基础并阐明舒张期吸力对左心室的重要性在生理和病理生理条件下填充。这由于我们实验室的最新进展，现在可以实现目标：首先，通过自动计算机化分析的能力植入放射性标记的立体视频图，数百个整个左边的同时三维应变心肌心肌；第二，左侧的新实验技术心房压力夹紧和左心室体积夹紧（伺服对照），它在揭示的初步测试中显示出希望第一次，左心室的机械相关性吸;第三，一种新的计算机图形方法来可视化大量同时瞬时区域应变和剪切允许识别空间和时间的模式，而不是否则，在诸如研究中引起的无数数据中都可以识别这些。拟议的研究解决了以下问题：（1）什么是可以在存在的情况下发展的吸气压力范围正常的二尖瓣瓣膜设备？（2）吸力对左心室填充的贡献？（3）是弹性的储存在心肌扭转变形中的能量这些剪切和这些剪切的压缩，平面应变或组合菌株？（4）弹性后坐力的区域分布和舒张期间区域能量释放的顺序以及如何影响LV内的压力梯度？（5）总计多少 LV填充可以由二尖瓣吞噬血液来解释向左中庭后坐力？（6）有什么影响伴随的病理生理状况（a）体积超负荷肥大和（b）区域舒张压上的压力超负荷肥大力学，收缩期间的弹性能量及其释放在舒张期以及LV发展吸力的能力？（7）以什么顺序和哪些比例存储在和释放中从结缔组织基质和心肌细胞中以帮助填充？这这些问题的答案应提供重要的新信息关于舒张功能的这些基本方面。

项目成果

期刊论文数量（28）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Mitral valve opening in the ovine heart.

绵羊心脏的二尖瓣开口。

DOI：
10.1152/ajpheart.1998.274.2.h552
发表时间：
1998
期刊：
The American journal of physiology
影响因子：
0
作者：
Karlsson,MO;Glasson,JR;Bolger,AF;Daughters,GT;Komeda,M;Foppiano,LE;Miller,DC;IngelsJr,NB
通讯作者：
IngelsJr,NB

Effects of mechanical left ventricular support on right ventricular diastolic function.

左心室机械支持对右心室舒张功能的影响。

DOI：
发表时间：
1997
期刊：
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation.
影响因子：
0
作者：
Moon,MR;DeAnda,A;Castro,LJ;Daughters2nd,GT;IngelsJr,NB;Miller,DC
通讯作者：
Miller,DC

Septal function during left ventricular unloading.

DOI：
10.1161/01.cir.95.5.1320
发表时间：
1997-03
期刊：
Circulation
影响因子：
37.8
作者：
M. Moon;A. Bolger;Abelardo DeAnda;M. Komeda;G. Daughters;S. Nikolic;D. C. Miller;N. Ingels
通讯作者：
M. Moon;A. Bolger;Abelardo DeAnda;M. Komeda;G. Daughters;S. Nikolic;D. C. Miller;N. Ingels

Effects of mitral valve replacement on regional left ventricular systolic strain.

二尖瓣置换术对局部左心室收缩应变的影响。