A MODEL OF CHRONIC ISCHEMIC HEART FAILURE

这项拟议的研究的目的是调查 可自由选择的、顺序的电血栓形成(ETG) 慢性(3个月)缺血性左心衰竭的实用模型。 几乎所有报道的模特要么成就太少--心脏 动物不会经历持久的变化--或太多--死亡。在建议的 技术8两端将被外化的电极将被植入 60只狗的左冠状动脉分支的管腔。在25年内 开胸术后恢复清醒的犬(A组) 电流将在其起始处附近施加6小时，以诱导 血栓(即电血栓形成，或ETG)。在狗康复后， 旋支(Cx)的分支将被ETG逐个阻塞，直到 肺毛细血管楔压(PCWP)>15 mm Hg。 然后这只狗将被饲养3个月，接受医疗 当PCWP大于20毫米汞柱时进行治疗。文件记录 狗对每个ETG的反应将包括心输出量和PCWP测量 在分级的跑步机运动中，和标准的临床观察。左边 开胸术后恢复后将进行冠状动脉电影血管造影 就在祭祀之前。左心功能曲线的比较 对临床数据的评估将确定最实用的方案。 同样的程序将在25只B组动物身上进行，只是 第一个ETG将应用于CX，后续的ETG将应用于 那个小伙子。C组5只犬作为对照。简化的协议 将在A组和B组结果的基础上制定，并遵循 D组5只，确认其实用性。 因为狗代表着建立一个 慢性故障模式，该协议如果成功，预计将 容易转移到更大的物种，如用于研究 机械循环辅助装置。

The purpose of the proposed research is to investigate the role of discretionary, sequential electrothrombogenesis (ETG) in the creation of a practical model of chronic (3-month) ischemic left ventricular failure. Nearly all reported models either accomplish too little--the heart undergoes no lasting change--or too much--the animal dies. In the proposed technique 8 electrodes whose ends will be exteriorized will be implanted in the lumina of left coronary artery branches in each of 60 dogs. In 25 conscious dogs that have recovered from thoracotomy (Group A), anodal current will be applied to the LAD near its origin for 6 hours to induce a thrombus (i.e., electrothrombogenesis, or ETG). After the dog's recovery, branches of the circumflex (CX) will be obstructed by ETG one by one until the pulmonary capillary wedge pressure (PCWP) is greater than 15 mm Hg. The dog will then be kept in failure for 3 months, receiving medical treatment when the PCWP is greater than 20 mm Hg. Documentation of the dog's response to each ETG will include cardiac output and PCWP measurement during graded treadmill exercise, and standard clinical observations. Left coronary cineangiography will be performed after recovery from thoracotomy and just before sacrifice. Comparison of left ventricular function curves and evaluation of clinical data will define the most practical protocol. The same procedure will be followed in 25 Group B animals, except that the first ETG will be applied to the CX and succeeding ones to the branches of the LAD. Five Group C dogs will serve as controls. A simplified protocol will be developed on the basis of the Group A and B results and followed in 5 Group D dogs to confirm its practicality. Since the dog represents the most difficult case for establishment of a chronic failure model, the protocol, if successful, is expected to be readily transferred to larger species, such as those used in study of mechanical circulatory assist devices.