Conductance to Measure Cardiac Mechanics

用于测量心脏力学的电导

• 批准号: 6335940
• 负责人: MARC David FELDMAN
• 金额: $ 13.92万
• 依托单位: MILLAR, INC.
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至 2002-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6335940
• 关键词: biomedical equipment development; blood pressure; electrical conductance; genetically modified animals; heart conduction system; heart contraction; heart ventricle; hemodynamics; laboratory mouse

DESCRIPTION (Applicant's Description Verbatim): The application of left ventricular pressure-volume relationships to transgenic mice to precisely measure contractility is not widely available. The long-term goal of this grant is to quantify left ventricular function in the intact mouse. Measurement of electrical conductance offers a method to generate an instantaneous left ventricular volume signal. The presently available instantaneous conductance output is a combination of blood and left ventricular muscle signals, but the blood volume (only) is desired. The problem can be solved by using two simultaneous frequencies, since myocardial resistivity varies with frequency while blood resistivity does not. The work will demonstrate that the dual frequency conductance system is superior to the standard single frequency system. A combination of experimental studies and numerical models will be used to calibrate the blood volume calculation when extracted from the combined blood and muscle signal. Finally, advances in instrumentation are proposed to move the dual frequency system to a closed-chest mouse preparation to enhance commercial interest. By removing the instantaneous myocardial contribution to the volume signal obtained during transient occlusion of the inferior vena cava, absolute measures of left ventricular contractility would be available. This would broaden the hemodynamic profile available from the intact murine left ventricle due to the wealth of information provided by pressure-volume analysis. PROPOSED COMMERCIAL APPLICATION: A dual frequency conductance system would allow scientists to precisely measure the complex phenotype of transgenic murine models of cardiovascular disease, such as congestive failure. Quantitation of left ventricular function would also allow the pharmaceutical industry to perform rapid screenting of new durgs in transgenic mice. The timing for these studies to understand the phenotype of selected genotypes is ideal as the Human Genome Project nears completion; and since humans and mice share a subset of highly conserved genes related to cardiovascular function.

描述（申请人的逐字描述）：左的应用 转基因小鼠的心室压力-容积关系 测量收缩性尚未广泛使用。本次资助的长期目标 目的是量化完整小鼠的左心室功能。测量 电导提供了一种产生瞬时左电势的方法 心室容积信号。目前可用的瞬时电导 输出是血液和左心室肌肉信号的组合，但是 （仅）需要血量。该问题可以通过使用两个来解决 同时频率，因为心肌电阻率随频率变化 而血液电阻率则不然。 这项工作将证明双频电导系统是 优于标准单频系统。实验的结合 研究和数值模型将用于校准血量 从组合的血液和肌肉信号中提取时的计算。最后， 建议仪器仪表的进步将双频系统转移到 闭胸小鼠制备以增强商业利益。 通过消除瞬时心肌对容量信号的贡献 在下腔静脉短暂闭塞期间获得，绝对 可以测量左心室收缩力。这会 拓宽完整小鼠左心室的血流动力学特征 由于压力体积分析提供了丰富的信息。 拟议的商业应用： 双频电导系统将使科学家能够精确测量 心血管疾病转基因小鼠模型的复杂表型，例如 充血衰竭。 左心室功能的定量也将允许药物 工业界在转基因小鼠中进行新药的快速筛选。 这些的时机 了解选定基因型表型的研究是人类基因组的理想选择 项目即将完成；由于人类和小鼠共享一个高度保守的子集 与心血管功能相关的基因。

项目成果

Enhancement of contractility with sustained afterload in the intact murine heart: blunting of length-dependent activation.

完整小鼠心脏持续后负荷增强收缩力：减弱长度依赖性激活。

• DOI: 10.1161/01.cir.0000070964.96190.67
• 发表时间: 2003
• 期刊: Circulation
• 影响因子: 37.8
• 作者: Reyes,Maricela;Freeman,GregoryL;Escobedo,Daniel;Lee,Shuko;Steinhelper,MarkE;Feldman,MarcD
• 通讯作者: Feldman,MarcD