Noninvasive Quantification of the Resistance Baroreflex

阻力压力反射的无创量化

• 批准号: 6966598
• 负责人: RAMAKRISHNA MUKKAMALA
• 金额: $ 18.96万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6966598
• 关键词: baroreflex; blood pressure; blood volume; cardiac output; dogs; heart rate; mathematical model; model design /development; noninvasive diagnosis; vascular resistance; baroreflex; blood pressure; blood volume; cardiac output; dogs; heart rate; mathematical model; model design /development; noninvasive diagnosis; vascular resistance

DESCRIPTION (provided by applicant): Feedback control of total peripheral resistance (TPR) by the arterial and cardiopulmonary baroreflex systems is an important mechanism for arterial blood pressure (ABP) regulation. Traditional techniques for measuring the TPR baroreflex aim to quantify the open-loop gain value of one baroreflex system. While multiple regression analysis (MRA) can determine the closed-loop gain values of both systems, this analysis mandates a sophisticated experimental preparation in which both heart rate and blood volume are perturbed and has therefore received little attention. Thus, the integrated functioning of both TPR baroreflex systems remains poorly understood. Our hypothesis is that both TPR baroreflex systems may be distinctly quantified from only the information present in naturally occurring, beat-to-beat hemodynamic variations. While this subtle variability has been the focus of many baroreflex studies in the past, it has not been exploited specifically for the characterization of the TPR baroreflex. We have developed a mathematical algorithm to quantify the closed-loop gain values of each TPR baroreflex by analyzing only beat-to-beat measurements of ABP and cardiac output (CO). We have demonstrated the feasibility of the algorithm in a single animal and in a small set of humans in which ABP and CO were noninvasively measured. We propose further development and rigorous evaluation of the algorithm in chronic animal studies. Specific Aim 1 is to validate the TPR baroreflex gain values determined by the mathematical algorithm. We will study up to15 conscious dogs with atrio-ventricular (AV) block and instrumented for cardiac pacing and measurement of ABP, CO, and central venous pressure (CVP). This experimental preparation will allow us to compare the TPR baroreflex gain values determined by applying the algorithm to ABP and CO measured during AV sequential pacing with reference values established by applying MRA to ABP, CVP, and CO measured during a set of adjustments to ventricular rate and blood volume. Specific Aim 2 is to demonstrate that the TPR baroreflex gain values determined by the mathematical algorithm are valid under various baroreflex states. We will repeat the above protocol after the administration of drugs that alter baroreflex functioning. Successful achievement of these specific aims may ultimately lead to a practical technique that is routinely employed to advance the basic understanding of the TPR baroreflex in both humans and animals in health and disease.

描述（由申请人提供）：动脉和心肺动反射系统对总周围电阻（TPR）的反馈控制是动脉血压（ABP）调节的重要机制。测量TPR BaroreFlex的传统技术旨在量化一个BaroreFlex系统的开环增益值。虽然多元回归分析（MRA）可以确定两个系统的闭环增益值，但该分析要求进行复杂的实验制备，其中心率和血液体积都受到干扰，因此很少受到关注。因此，两个TPR屈光系统的综合功能仍然尚不清楚。我们的假设是，这两个TPR BaroreFlex系统都可以明确地量化，仅与天然发生的，搏动的血液动力学变化中存在的信息。尽管这种微妙的变异性过去一直是许多BaroreFlex研究的重点，但并未专门针对TPR BaroreFlex的表征。我们已经开发了一种数学算法来通过仅分析ABP和心脏输出（CO）的Beat-Beat测量值来量化每个TPR BaroreFlex的闭环增益值。我们已经证明了该算法在单个动物中的可行性，以及在无创测量ABP和CO的一小部分人中。我们建议对慢性动物研究中的算法进行进一步的发展和严格评估。具体目的1是验证由数学算法确定的TPR BaroreFlex增益值。我们将使用心室（AV）区块研究15只意识的狗，并进行仪器，用于ABP，CO和中央静脉压力（CVP）的心脏起搏和测量。这项实验制备将使我们能够比较通过将算法应用于ABP和ABP和CO确定的TPR BaroreFlex增益值，并在ABP和CO中使用通过将MRA应用于ABP，CVP和CO在心室速率和血液体积的一组调整期间测量的参考值确定。具体目的2是证明由数学算法确定的TPR BaroreFlex增益值在各种BaroreFlex状态下都是有效的。我们将在施用改变压力反射功能的药物后重复上述方案。这些特定目标的成功实现最终可能导致一种实用的技术，该技术通常被用来促进人类和动物在健康和疾病中对TPR Baroreflex的基本理解。