EXERCISE TRAINING EFFECT ON DIASTOLIC DYSFUNCTION

最近人们认识到，舒张性功能障碍是一种常见的 心力衰竭的原因，特别是在老年人中。运动不耐受是一种 充血性心力衰竭的突出症状，也是致残的重要原因。然而，在 与由于收缩功能障碍引起的CHF相比，几乎没有信息是 关于运动耐量不足的病理生理学方面的资料 有舒张期功能障碍的患者。我们之前的工作表明 原发性舒张期功能障碍患者的运动耐量可能是 由于运动过程中舒张末容量反应明显受限。 健康受试者进行有氧运动训练可增加运动终末 舒张期容量和几个可能预期的其他修改 目的：提高舒张期功能障碍患者的运动耐量。 尽管这项干预可以改善舒张期功能障碍和锻炼 不容忍可能会对老年人的残疾产生重大影响， 运动训练对这些患者的效果尚不清楚。因此， 这项研究的主要目的是检验以下假设：1)老年人 患有原发性舒张期功能障碍的患者有运动不耐受和 这与增加舒张末的能力减弱有关。 容量(左心室扩张性)，以及2)运动训练将改善运动 耐受性和LV扩张性。 在横断面设计中，50名年龄等于或超过65岁的患者 原发性舒张期功能障碍(慢性心力衰竭的临床症状和体征 存在正常的左心室射血分数，没有临床或 显著冠状动脉或瓣膜心脏的超声心动图证据 将与年龄和性别匹配的健康受试者进行比较。 然后，这50名患者将进入随机、对照、单盲 16周有氧运动训练干预试验。最大氧气 将通过呼出气体分析和舒张期结束来测量消耗量 音量和冲程音量将通过二维测量 休息、运动和仰卧位时的超声心动图。其他 测量将包括自我健康相关的生活质量 对循环中的去甲肾上腺素进行调查和分析， 血管紧张素-II、醛固酮和心钠素。 这项研究将解决重要的基本问题，涉及 老年心力衰竭患者运动耐量异常的机制 和正常的左心室射血分数，并将测试一个 进行合理的生理干预以改善舒张期功能， 锻炼耐力和生活质量。这一信息具有重大意义 对老年人保健和残疾的影响。

It has recently been recognized that diastolic dysfunction is a common cause of CHF, particularly among the elderly. Exercise intolerance is a prominent symptom of CHF and an important cause of disability. However in contrast to CHF due to systolic dysfunction, little information is available regarding the pathophysiology of exercise intolerance in patients with diastolic dysfunction. Our previous work suggests that exercise intolerance in patients with primary diastolic dysfunction may be due to markedly limited end diastolic volume response during exercise. Aerobic exercise training in healthy subjects results in increased end diastolic volume and several other modifications which might be expected to improve exercise tolerance in patients with diastolic dysfunction. Although an intervention that improves diastolic dysfunction and exercise intolerance could have a major impact on disability in the elderly, the effect of exercise training in these patients is unknown. Therefore the primary aim of this study will be to test the hypotheses that 1) elderly patients with primary diastolic dysfunction have exercise intolerance and this is associated with diminished ability to increase end-diastolic volume (LV distensibility), and 2)exercise training will improve exercise tolerance and LV distensibility. In a cross-sectional design, 50 patients equal to or more than age 65 with primary diastolic dysfunction (clinical symptoms and signs of CHF in the presence of a normal left ventricular ejection fraction and no clinical or echocardiographic evidence of significant coronary or valvular heart disease) will be compared with age and gender matched healthy subjects. The 50 patients will then enter a randomized, controlled, single blinded 16-week intervention trial of aerobic exercise training. Maximal oxygen consumption will be measured by expired gas analysis, and end diastolic volume and stroke volume will be measured by 2-dimensional echocardiography during rest, exercise and head-up tilt. Other measurements will include health related quality of life by self- administered surveys and assays for circulating norepinephrine, angiotensin-II, aldosterone, and atrial natriuretic factor. This study will address important fundamental questions regarding the mechanisms of exercise intolerance in elderly patients with heart failure and normal left ventricular ejection fractions, and will test a physiologically rational intervention to improve diastolic function, exercise tolerance and quality of life. This information has major implications for health care and disability in the elderly.