Relation of apex-to-base dispersion in diastolic lengthening to left ventricular diastolic function evaluated by tissue tracking system

方法：对27例非阻塞性HCM患者和25名健康志愿者进行左室基底和根尖短轴观察。在每个视图中放置舒张末期心肌内膜上的8个等角点，并使用二维超声心动图组织跟踪系统自动跟踪这些点的运动。得到Time-LV径向缩短曲线并求平均值。测量各视图主动脉瓣关闭至峰值延长前40%点（T_<40>）的时间间隔。结果：HCM组T_<40>与根尖（Δ-T_<40>）的时间差大于对照组。Δ-T_<40>与左室舒张早期回声参数及左室质量指数呈良好的线性相关。结论：我们的研究结果表明，心尖不均匀导致心尖至基底延长的主动机械协调性丧失，这可能导致整体左室舒张损害。

METHODS : We obtained basal and apical LV short-axis views in 27 patients with non-obstructive HCM and 25 healthy volunteers. Eight equiangular points on the endo-myocardium at end-diastole were placed in each view, and the movements of these points were automatically tracked using a two-dimensional echocardiographic tissue tracking system. Time-LV radial shortening curves were obtained and averaged. The time intervals from the aortic valve closure to the point of the first 40% of peak lengthening (T_<40>) were measured in each view. RESULTS : The time difference in the T_<40> between the apex and base (Δ-T_<40>) in the HCM group was greater than that in the control group. There were good linear correlations between the Δ-T_<40> and the LV early diastolic echo-parameters and the LV mass index. CONCLUSIONS : Our results suggested that apical non-uniformity resulted in loss of active mechanical coordination of apex-to-basal lengthening, which could contribute to global LV diastolic impairment.