ASPECTS OF DIASTOLIC FUNCTION IN THE CANINE HEART

该提案包括三个项目，旨在提供更好的 对心脏周围外力性质的理解。 首先，我将检验心包贴靠力随 心脏表面上的区域与心脏的动态体积相关， 地下室 我将测量这些接触力， 气球，此外，通过使用声显微测量法来测量局部区域 心包膜 在本项目的第二部分中，我将测试 假设心包是早期左心室的决定因素 充填动力学 在第二个项目中，我将描述 心脏和心包的相互关系在过程中 实验性慢性容量超负荷，由于全身动静脉 瘘或主动脉瓣返流。 我建议心包和心脏 不要平行生长。 因此，在整个过程中的某个时候， 容量超负荷心包对心脏充盈的影响将 被夸大了。 最后，在第三个项目中，我将评估 直接舒张心室相互作用的生理幅度， 一种最近开发的技术，其中心脏体积在一个 舒张周期 这项技术将用于评估与 胸部闭合或打开，并具有不同的通气模式和阶段。

This proposal contains three projects designed to provide a better understanding of the nature of the external forces around the heart. First, I will test the hypothesis that pericardial contact forces vary by region over the surface of the heart in relation to the dynamic volumes of the underlying chambers. I will measure these contact forces with flat balloons and in addition by using sonomicrometry to measure localized areas of the pericardium. In a second portion of this project, I will test the hypothesis that the pericardium is a determinant of early left ventricular filling dynamics. In the second project, I will delineate the interrelationships of the heart and the pericardium during the course of experimental chronic volume overload due to either a systemic arteriovenous fistula or aortic regurgitation. I propose that the pericardium and heart do not grow in parallel. As a result, at some time during the course of volume overload the effect of the pericardium on filling of the heart will be exaggerated. Finally, in the third project I will assess the physiological magnitude of direct diastolic ventricular interaction using a recently developed technique in which cardiac volume is changed over one diastolic cycle. This technique will be applied to assess interaction with chest closed or open and with differing modes and phases of ventilation.