Diastolic dysfunction as a cause of exercise intolerance.
Diastolic dysfunction as a cause of exercise intolerance.
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DOI：
10.1023/a:1026503028065
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发表时间：
2000-12-01
影响因子：
4.6
通讯作者：
Cheng, C P
中科院分区：
文献类型：
--
作者：
Little, W C;Kitzman, D W;Cheng, C P
伴随运动的心动过速缩短了心搏的持续时间，减少了左心室（LV）充盈的时间。因此，LV必须更快地充盈，以使每搏输出量在运动期间增加（或甚至维持）。通常，这是在不需要通过运动期间LV舒张加速和LV早期舒张压下降而过度增加左心房（LA）压力的情况下实现的。在实验动物和患者中，由于收缩功能障碍，这种反应在心力衰竭发展后丧失。事实上，在这种情况下，由于运动，LV舒张减慢，LV早期舒张压增加。因此，在收缩功能障碍期间CHF中静息时存在的任何舒张功能障碍在运动期间加重。类似地，患有原发性舒张功能障碍心力衰竭且收缩功能保留的患者可能无法在没有LA压力异常升高的情况下增加LV充盈率。因此，舒张功能障碍可能有助于运动不耐受，无论是在收缩功能障碍和原发性舒张功能障碍。急性研究表明，血管紧张素II受体阻滞剂或维拉帕米治疗可改善某些原发性舒张功能障碍患者的运动耐量。
Tachycardia accompanying exercise shortens the duration of diastole, reducing the time available for the left ventricular (LV) filling. Thus, the LV must fill more rapidly for the stroke volume to increase (or even be maintained) during exercise. Normally, this is accomplished without requiring an excessive increase in left atrial (LA) pressure by an acceleration of LV relaxation and a fall in LV early diastolic pressure during exercise. This response is lost following the development of heart failure due to systolic dysfunction, both in experimental animals and in patients. In fact, in such situations, LV relaxation slows and LV early diastolic pressure increases due to exercise. Thus, any diastolic dysfunction present at rest in CHF during systolic dysfunction is exacerbated during exercise. Similarly, patients with primary diastolic dysfunction heart failure with preserved systolic function may not be able to augment LV filling rates without an abnormal increase in LA pressure. Thus, diastolic dysfunction may contribute to exercise intolerance, both in systolic dysfunction and primary diastolic dysfunction. Acute studies suggest that treatment with angiotensin II receptor blockers or verapamil may improve exercise tolerance in some patients with primary diastolic dysfunction.