Ventricular Restraint Therapy for Heart Failure

描述(申请人提供)：这项建议的主要假设是，在扩张的衰竭心脏中，心室约束疗法可以降低跨壁压、舒张末容量和心肌耗氧量，以促进反向重构。先前的动物研究和初步临床研究证明了心室约束疗法的前景和可行性，但仍存在许多问题。我们实验室开发了一种新型的心室约束装置，能够通过使用心外膜球囊进行定量的心室约束。我们的第一个具体目标是测量整个心动周期的跨室壁压力和左心室容量，推导出压力-体积关系，并使用定量的心室束缚计算压力-体积面积。这一目的将证明在正常心脏中，心室束缚对心室力学和能量学的影响。我们还将研究心室束缚对心肌灌注的急性影响。我们的第二个目标是在绵羊心肌梗死后的扩张型心肌病模型中进行同样的测量。我们将在为期3个月的纵向研究中进行一系列测量，以评估舒张末容量、心室收缩能力、心肌灌注，以及与对照组动物相比，心室约束组的逆转重塑的证据。这些目标的成功完成将使人们更好地了解心室束缚对心室生理学的影响。

DESCRIPTION (provided by applicant): The major hypothesis of this proposal is that ventricular restraint therapy reduces transmural pressure, end-diastolic volume, and myocardial oxygen consumption to promote reverse remodeling in a dilated failing heart. Prior animal and initial clinical studies demonstrate the promise and feasibility of ventricular restraint therapy, however many questions remain. Our lab has developed a novel ventricular restraint device capable of quantitative ventricular restraint through the use of an epicardial balloon. Our first specific aim is to measure transmural pressure and left ventricular volume throughout the cardiac cycle, derive the pressure-volume relationship and calculate the pressure-volume area using quantitative ventricular restraint in a normal ovine heart. This aim will demonstrate the effect of ventricular restraint on ventricular mechanics and energetics in a normal heart. We will also examine the acute effect of ventricular restraint on myocardial perfusion. Our second aim is to perform these same measurements in an ovine post-infarcted model of dilated cardiomyopathy. We will perform serial measurements over a 3-month longitudinal study to evaluate end-diastolic volume, ventricle contractility, myocardial perfusion, and evidence of reverse remodeling in ventricular restraint versus control animals. Successful completion of these aims will, lead to a better understanding of the effect of ventricular restraint on ventricular physiology.