LEFT VENTRICULAR-ARTERIAL COUPLING

左心室-动脉耦合

• 批准号: 3360529
• 负责人: William C. Little
• 金额: $ 18.06万
• 依托单位: WAKE FOREST UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3360529
• 关键词: cardiovascular disorder; coronary vasodilator; dogs; exercise; heart failure; heart ventricle; intracardiac pressure; intracardiac volume; rest; vascular resistance

The performance of the cardiovascular system depends on the interaction of its components. We propose to investigate the coupling of the left ventricle (LV) and arterial systems in conscious animals with intact reflexes at rest, during exercise, and with depressed LV performance. The analysis of LV and arterial pressure (P)-volume (V) relations to be used in these studies is based on previous observations in the isolated LV ejecting into a model of the arterial system. These concepts have not been evaluated in the circulation of intact, conscious animals and the effects of exercise and clinically important disease processes have not been previously investigated. The following specific hypotheses will be evaluated. Hypothesis 1: The stroke volume (SV) and the LV end-systolic P (PES) are linearly related over the physiologically relevant range. The slope of this relation, EA, is the effective elastance of the arterial system, and is primarily determined under most circumstances by the heart rate and total peripheral vascular resistance. Hypothesis 2: LV stroke work is maximal when end-systolic elastance of the LV (EES) is equal to EA, while mechanical efficiency (the ratio of arterial stroke work to total pressure-volume area, SW/PVA) is maximum when EES is greater than EA. Hypothesis 3: The normal cardiovascular system operates at rest with EES slightly greater than EA, intermediate between points for maximum SW and mechanical efficiency. Hypothesis 4: During exercise, the LV and arterial system function closer to the point of maximum mechanical efficiency with EES > EA; similar increases in heart rate produced by pacing at rest result in suboptimal matching with EES < EA, Hypotheses 5 and 6: When LV function is depressed by rapid pacing induced heart failure or coronary occlusion, the coupling of the LV and arterial system is not optimal, as EA > EES, but can be returned toward optimal by decreasing EA using vasodilators. Hypothesis 1 will be evaluated both in an anesthetized, open-chest preparation in which stroke volume can be precisely controlled by right heart bypass in conscious dogs. The other hypotheses will be evaluated by studying conscious dogs previously instrumented to measure LV pressure and volume. EES will be determined as the slope of the LV end- systolic pressure-volume relation produced by varying LV P and V by transient caval occlusions. EA will be determined as PES/SV. These studies will supply important new information on the coupling of the LV and arterial system of the conscious animal with intact reflexes at rest, during exercise, and following depression of LV performance. These studies may lead to rational interventions to improve pump function in patients with common cardiovascular diseases.

心血管系统的性能取决于 它的组件。 我们建议调查左侧的耦合 有意识的动物的心室（LV）和动脉系统完好无损 静止，运动过程中的反射以及LV性能降低。这 LV和动脉压（P） - 体积（V）的分析 这些研究基于以前的观察结果 进入动脉系统的模型。 这些概念不是 在完整，有意识的动物的循环中评估 运动和临床上重要的疾病过程尚未 先前已调查。 以下特定假设将是 评估。 假设1：中风体积（SV）和LV末端音节 P（PE）在生理相关范围内线性相关。 这 这种关系的斜率EA是动脉的有效弹性 系统，主要是在大多数情况下确定的 速率和总周围血管抗性。 假设2：LV中风 当LV（EES）的末端局势弹性等于EA时，工作是最大的 而机械效率（动脉中风工作与总数的比率 当EES大于EA时，压力卷面积，SW/PVA）最大。 假设3：正常的心血管系统与EES保持静止 略大于EA，最大SW的点之间中间 机械效率。 假设4：在运动过程中，LV和动脉 系统功能更接近最大机械效率的点 ees> ea;在休息结果下起搏会产生类似的心率增加 在与EES <EA的次优匹配中，假设5和6：当LV时 快速起搏引起的心力衰竭或冠状动脉降低功能 闭塞，LV和动脉系统的耦合不是最佳的，因为EA > ees，但可以通过使用使用EA来减少EA 血管扩张器。 假设1将在麻醉的开放式胸前评估 可以精确控制中风音量的准备工作 有意识的狗的心脏绕过。 其他假设将通过 研究有意识的狗以前有仪器以测量LV压力和 体积。 EES将被确定为LV末端收缩期的斜率 由瞬态骑士变化的LV P和V产生的压力体积关系 闭塞。 EA将被确定为PES/SV。 这些研究将提供有关耦合的重要新信息 具有完整反射的有意识动物的LV和动脉系统 休息，在运动过程中，并遵循LV性能的抑郁。这些 研究可能会导致合理的干预措施，以改善泵的功能 常见心血管疾病的患者。