Mechanisms of exercise intolerance - Insights from tissue Doppler imaging
Mechanisms of exercise intolerance - Insights from tissue Doppler imaging
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DOI：
10.1161/01.cir.0000117405.74491.d2
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发表时间：
2004-03-02
期刊：
影响因子：
37.8
通讯作者：
Litwin, SE
中科院分区：
文献类型：
--
作者：
Skaluba, SJ;Litwin, SE
Background - A decreased ratio of early to late diastolic mitral inflow velocities ( E/ A < 1.0) reflects slowing of left ventricular ( LV) relaxation. This finding is widely believed to indicate significant diastolic dysfunction. However, E/ A < 1.0 is common during normal aging and often is not associated with symptoms of heart failure. We asked ( 1) whether slowed LV relaxation is associated with exercise intolerance and ( 2) whether tissue Doppler imaging of the early diastolic mitral annular velocity ( Ea) is helpful in understanding mechanisms of exercise intolerance.Methods and Results - Patients ( n = 121) underwent echocardiography before maximal exercise testing. Fifty- nine subjects had E/ A < 1.0, and 36 subjects had E/ Ea >= 10. Exercise capacity was similar in the population with a normal mitral inflow pattern and those with a slow relaxation pattern when E/ Ea was < 10. In contrast, the subjects with slow relaxation and E/ Ea greater than or equal to 10 had reduced exercise tolerance. Of all the echo and clinical parameters assessed, E/ Ea had the best correlation with exercise capacity ( r = - 0.684, P < 0.001) and was the strongest independent predictor of exercise capacity
