van Dalen Bas M, Soliman Osama I I, Vletter Wim B, ten Cate Folkert J, Geleijnse Marcel L
The Department of Cardiology, The Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands.
Am J Physiol Heart Circ Physiol. 2008 Oct;295(4):H1705-11. doi: 10.1152/ajpheart.00513.2008. Epub 2008 Aug 22.
The increasing number and proportion of aged individuals in the population warrants knowledge of normal physiological changes of left ventricular (LV) biomechanics with advancing age. LV twist describes the instantaneous circumferential motion of the apex with respect to the base of the heart and has an important role in LV ejection and filling. This study sought to investigate the biomechanics behind age-related changes in LV twist by determining a broad spectrum of LV rotation parameters in different age groups, using speckle tracking echocardiography (STE). The final study population consisted of 61 healthy volunteers (16-35 yr, n=25; 36-55 yr, n=23; 56-75 yr, n=13; 31 men). LV peak systolic rotation during the isovolumic contraction phase (Rot(early)), LV peak systolic rotation during ejection (Rot(max)), instantaneous LV peak systolic twist (Twist(max)), the time to Rot(early), Rot(max), and Twist(max), and rotational deformation delay (defined as the difference of time to basal Rot(max) and apical Rot(max)) were determined by STE using QLAB Advanced Quantification Software (version 6.0; Philips, Best, The Netherlands). With increasing age, apical Rot(max) (P<0.05), time to apical Rot(max) (P<0.01), and Twist(max) (P<0.01) increased, whereas basal Rot(early) (P<0.001), time to basal Rot(early) (P<0.01), and rotational deformation delay (P<0.05) decreased. Rotational deformation delay was significantly correlated to Twist(max) (R(2)=0.20, P<0.05). In conclusion, Twist(max) increased with aging, resulting from both increased apical Rot(max) and decreased rotational deformation delay between the apex and the base of the LV. This may explain the preservation of LV ejection fraction in the elderly.
人口中老年个体数量及其所占比例的不断增加，使得了解随着年龄增长左心室（LV）生物力学的正常生理变化变得很有必要。左心室扭转描述了心尖相对于心底的瞬时圆周运动，并且在左心室射血和充盈过程中发挥重要作用。本研究旨在通过使用斑点追踪超声心动图（STE）测定不同年龄组的一系列广泛的左心室旋转参数，来探究左心室扭转的年龄相关变化背后的生物力学机制。最终的研究人群包括61名健康志愿者（年龄16 - 35岁，n = 25；36 - 55岁，n = 23；56 - 75岁，n = 13；男性31名）。使用QLAB高级定量软件（版本6.0；飞利浦公司，荷兰贝斯特）通过STE测定等容收缩期左心室峰值收缩期旋转（Rot(early)）、射血期左心室峰值收缩期旋转（Rot(max)）、瞬时左心室峰值收缩期扭转（Twist(max)）、达到Rot(early)、Rot(max)和Twist(max)的时间，以及旋转变形延迟（定义为心底达到Rot(max)的时间与心尖达到Rot(max)的时间之差）。随着年龄的增长，心尖Rot(max)（P < 0.05）、达到心尖Rot(max)的时间（P < 0.01）和Twist(max)（P < 0.01）增加，而心底Rot(early)（P < 0.001）、达到心底Rot(early)的时间（P < 0.01）和旋转变形延迟（P < 0.05）减少。旋转变形延迟与Twist(max)显著相关（R(2)=0.20，P < 0.05）。总之，Twist(max)随着年龄增长而增加，这是由于心尖Rot(max)增加以及左心室心尖与心底之间的旋转变形延迟减少所致。这可能解释了老年人左心室射血分数得以保留的原因。
