EXERCISE TRAINING/DIASTOLIC HEART FAILURE IN THE ELDERLY

舒张性心力衰竭占心力衰竭病例的50%以上 在65岁以上的人口中是一项重要的医疗保健 对美国老年人来说是个问题。我们目前的研究表明 老年舒张性心力衰竭患者进行剧烈运动 这种情况会随着运动训练的改善而得到改善。然而， 只有不到30%的改善可归因于 心输出量。这表明，受损的人可能会扮演一个角色 通过降低肌肉灌注量来调节外周血管。我们的 试点数据表明，在老年舒张性心力衰竭患者中 内皮依赖性血流介导的动脉扩张(FMAD)是 严重受损，与运动能力相关，并 运动训练后有所增加。这项研究的主要目的 将对60名老年人进行初步横断面比较 舒张性心力衰竭患者(症状性心力衰竭，正常 左心室射血分数，无明显冠脉或瓣膜心脏 疾病或肺部疾病)与匹配的健康正常人 然后将患者纳入随机、对照、单一的 有氧运动训练的盲法试验 具体假设如下：1.老年舒张性心力衰竭 与年龄和性别相比，患者的FMAD减少 与健康的正常受试者匹配。2.运动不耐受 老年舒张性心力衰竭患者心脏功能减退 FMAD。3.运动训练对老年心力衰竭患者的影响 提高FMAD和运动能力。4.改善 运动能力将与FMAD的改善相关。一个 次要目标是检查FMAD与其他 心室-血管偶联的决定因素。原理 测量指标包括肱动脉FMAD和颈动脉指数 高分辨率超声检测动脉硬化；脉搏波速度 通过眼压测量；最大和次最大氧耗量和 呼出气体分析的呼吸机无菌阈值和心脏 通过数字超声心动图测量心脏体积。这项研究将评估 血管内皮功能障碍在运动耐量增加中的作用 舒张性心力衰竭使用生理上合理，广泛 适用的干预措施。

Diastolic heart failure accounts for over 50% of heart failure cases in the population greater than 65 and is an important health care problem for older Americans. Our current research shows that elderly patients with diastolic heart failure have severe exercise intolerance and that this improves with exercise training. However, less than 30% of the improvement is attributable to increased cardiac output. This suggests a potential role for impaired peripheral vasoregulation by compromising muscle perfusion. Our pilot data suggest that in elderly diastolic heart failure patients endothelial dependent flow mediated arterial dilation (FMAD) is substantially impaired, correlates with exercise capacity, and is increased after exercise training. The primary aims of this study are to perform an initial cross-sectional comparison of 60 elderly diastolic heart failure patients (symptomatic heart failure, a normal LV ejection fraction and no significant coronary or valvular heart disease or pulmonary disease) with matched healthy normal subjects and then to enter the patients into a randomized, controlled, single blinded trial of aerobic exercise training in order to test the following specific hypotheses: 1. Elderly diastolic heart failure patients have decreased FMAD compared to age and gender matched healthy normal subjects. 2. Exercise intolerance in elderly diastolic heart failure patients is associated with decreased FMAD. 3. Exercise training in elderly heart failure patients will improve FMAD and exercise capacity. 4. Improvements in exercise capacity will correlate with improvements in FMAD. A secondary aim is to examine relationship between FMAD and other determinants of ventricular-vascular coupling. Principle measurements include brachial artery FMAD and indexes of carotid artery stiffness by high resolution ultrasound; pulse wave velocity by tonometry; maximal and submaximal oxygen consumption and ventilatory anerobic threshold by expired gas analysis, and cardiac volumes by digital echocardiography. This study will assess the contribution of endothelial dysfunction to exercise intolerance in diastolic heart failure using a physiologically rational, widely applicable intervention.