King G J, Murphy R T, Almuntaser I, Bennett K, Ho E, Brown A S
Cardiology Department, St James's Hospital, James's Street, Dublin 8, Ireland.
Heart. 2008 Oct;94(10):1323-5. doi: 10.1136/hrt.2008.142083. Epub 2008 May 12.
In elite athletes left ventricular (LV) morphological changes are predicted to alter passive pressure/volume characteristics by reducing myocardial stiffness and increasing compliance.
To investigate the utility of a new Doppler tissue index based on the pressure volume relation ((E/Ea)/LVEDD), which provides a measure of myocardial stiffness, and to assess its usefulness in detecting cardiac adaptation in elite rowers.
Thirty-six international rowers who had trained intensively and a control group of 30 sedentary subjects, matched for age and sex, were enrolled in the study. LV septal and posterior wall thickness, mass, chamber size, transmitral Doppler peak early (E) and late (A) diastolic filling velocities and isovolumic relaxation times were measured. Early diastolic myocardial velocities (Ea) were averaged from four sites at the mitral annulus; diastolic stiffness was assessed with the use of three indices E, Ea and the LV end-diastolic diameter in diastole (LVEDD). The ratio, (E/Ea)/LVEDD, provides a new index of diastolic stiffness. Rowers were further divided into two groups based on the presence or absence of left ventricular hypertrophy (LVH) <or=12 mm and >12 mm.
No significant difference in Ea was found between the two groups, but there was a difference in the stiffness index, which remained after adjustment for body surface area and heart rate (controls 1.48 (0.3) vs athletes 1.17 (0.34), p = 0.016). No difference in stiffness index was found between the groups with LVH <or=12 mm and >12 mm (1.11 (0.32) vs 1.17 (0.34), respectively, p = 0.68)
Intense training reduces myocardial stiffness despite the development of LVH.
在精英运动员中，预计左心室（LV）形态变化会通过降低心肌僵硬度和增加顺应性来改变被动压力/容积特性。
研究基于压力-容积关系的新型多普勒组织指数（(E/Ea)/LVEDD）的实用性，该指数可测量心肌僵硬度，并评估其在检测精英赛艇运动员心脏适应性方面的作用。
本研究纳入了36名经过强化训练的国际赛艇运动员以及30名年龄和性别匹配的久坐不动的对照组受试者。测量左心室间隔和后壁厚度、质量、腔室大小、二尖瓣舒张早期（E）和晚期（A）峰值充盈速度以及等容舒张时间。舒张早期心肌速度（Ea）取二尖瓣环四个部位的平均值；使用E、Ea和舒张末期左心室直径（LVEDD）三个指标评估舒张期僵硬度。比值(E/Ea)/LVEDD提供了一个新的舒张期僵硬度指数。根据左心室肥厚（LVH）是否≤12mm和＞12mm，将赛艇运动员进一步分为两组。
两组之间Ea无显著差异，但僵硬度指数存在差异，在调整体表面积和心率后该差异仍然存在（对照组1.48(0.3)，运动员组1.17(0.34)，p = 0.016）。LVH≤12mm和＞12mm的两组之间僵硬度指数无差异（分别为1.11(0.32)和1.17(0.34)，p = 0.68）。
尽管出现了LVH，但高强度训练可降低心肌僵硬度。
