摘要
目的 :探讨室壁应力 ( stress)与应变 ( strain)的关系及其评价高血压左室收缩功能的临床意义。方法 :研究对象为 5 5例高血压病人和 3 0例健康人。应用超声心动图计算左室射血分数 ( EF)、心排血指数 ( CI)、左心室质量指数 ( LVMI)和相对室壁厚度 ( RWT) ,并联合袖带肱动脉血压值计算左心室收缩期经线峰值室壁应力( Pσm )。应用定量组织速度成像 ( QTVI)获取左室前壁中段心肌长轴应变曲线和峰值收缩应变值 ( PSS)。结果 :1高血压组 Pσm显著增高 ,而 PSS显著降低 ( P<0 .0 5～ 0 .0 1 )。 2直线相关分析结果显示 Pσm与 PSS呈显著负相关 r=-0 .66,P <0 .0 1 )。 3在相同 Pσm水平下 ,左室重构组 PSS实测值及实测值与预测值的比值较正常构型组显著下降 ( P <0 .0 1 )。结论 :1高血压左室室壁应力与应变呈显著负相关。 2室壁应力与应变的关系不依赖心脏后负荷 ,能够早期评价高血压左室收缩功能和更客观地反映心肌本身的生物力学特性 。
Objective: To explore the relationship between the left ventricular(LV)wall stress and strain for evaluating the clinical significance of LV systolic function in hypertension. Methods: The LV wall meridional peak systolic stress (Pσm ) and LV mass index (LVMI) and relative wall thickness (RWT) and ejection fraction (EF) and cardiac index (CI) were assessed by echocardiography and brachial blood pressure in 55 cases of essential hypertension and 30 normal control subjects. Applying quantitative tissue velocity imaging (QTVI) to obtain the middle segment of LV anterior wall long-axis strain curve, and peak systolic strain were measured. Results: ①In hypertension groups, Pσm was significantly higher, and PSS was significantly lower than those in the healthy group($P$<0.05～0.01). ②There was high negative correlation between Pσm and PSS in hypertension($r$=-0.66, $P$<0.01). ③At the same stress level, the measured value of the PSS was significantly lower than the estimated value of the PSS and the ratio of the measured value and the estimated value of the PSS in remodelling geometric group decreased significantly than in normol geometric group ($P$<0.01). Conclusion: ①There was high negative correlation between Pσm and PSS in hypertension. ②Relationship of LV wall stress and strain was independent of afterload status. Applying the relationship of LV wall stress and strain to evaluate the myocardial contractility can reflect biomechanical character of myocardium more objectively, and it may be a useful method in evaluating the pathophysiological changes of myocardium in vivo.;
出处
《内蒙古医学院学报》
2004年第4期258-262,共5页
Acta Academiae Medicinae Neimongol
基金
内蒙古科学技术委员会资助
内蒙古卫生厅资助 ( 2 0 0 0 1 3 0 6)
关键词
组织速度成像
高血压
应力
应变
左室功能
tissue velocity image
hypertension
stress
strain
left ventricular function
