文章来源:未知 文章作者:meng 发布时间:2009-12-09 01:10 字体: [ ]  进入论坛

Using a new noninvasive非侵害的 imaging technique, scientists said they have discovered important, fundamental differences in heart motion by age and gender1. Their study — reported in Circulation: Cardiovascular心脏血管的 Imaging, a journal of the American Heart Association — is the first to provide gender- and age-specific data on the motions of the normal heart based on a regional analysis地区分析 of myocardial心肌的 velocities速度,速率 covering all 16 segments of the left ventricle左心室.

The results, obtained with magnetic resonance3 imaging核共振成像 (MRI) tissue phase mapping, are the most precise measurements yet of the left ventricle's complex motions as it contracts and relaxes with each heartbeat.

"This information could change the diagnosis4 and assessment5 of heart disease from its earliest stages," said Daniela Föll, M.D., lead author of the study and a senior consultant6顾问 in cardiology心脏学 at University Hospital Freiburg in Germany.

The healthy heart performs a complex wringing7 motion with each beat. The base of the left ventricle changes its direction of rotation旋转方向 up to six times per beat. The ventricle's top rotates counterclockwise逆时针旋转 during contraction9 and clockwise during relaxation10.

According to Föll, as heart problems develop, various regions of the left ventricle — which pumps blood through the body — change the speed at which they move during each beat.

"MRI enables a complete analysis of muscle motion within the entire left ventricle," she said. "Knowledge of the exact distribution and timing11 of the velocities2 within the ventricle is essential for the exact understanding of the muscle performance in heart disease."

The researchers obtained specific movement data from three adult age groups: 20, 41 and older than 60 years. They studied 29 male and 29 female healthy volunteers.

"The pronounced显著的,断然的 age- and gender-related differences that we described stress the necessity of age- and gender-matched control groups in studies evaluating heart-muscle function," Föll said.

She said further research is needed to verify the accuracy of what the small study shows. "If additional trials confirm the findings, MRI tissue phase mapping will optimally12 serve as a complement13 to the echocardiograms超声心动图 now used in diagnosing heart disease."

The MRI technology provided images of the ventricle's motions with high temporal当时的,暂时的 resolution of 14 ms.

Among the study's specific findings:
Age and gender strongly influenced the regional motion of the heart muscle during relaxation and contraction.
Contrary to reports from earlier studies, apex14顶点,最高点 rotation8 speed decreased with aging.
Among young participants, women had higher up-and-down motion velocities along the long-axis of the ventricle than men. However, these motion speed differences were reversed in older volunteers. Therefore, the MRI images identified a greater decline in women than men in muscle shortening and expansion from the ventricle's base to its top during both contraction and relaxation.
Women showed reduced twisting of the ventricle, apex rotation and lower muscle velocity15 towards the left ventricular center during contraction compared to men.
Age-related changes in peak motion speeds persisted after the team considered differences in left ventricle shape and blood pressure.

"We were surprised by the differences of myocardial motion we found in women, which were not all explained by anatomical结构上的,解剖学的 differences," Föll said.


1 gender slSyD     
  • French differs from English in having gender for all nouns.法语不同于英语,所有的名词都有性。
  • Women are sometimes denied opportunities solely because of their gender.妇女有时仅仅因为性别而无法获得种种机会。
2 velocities 64d80206fdcbbf917808c5b00e0a8ff5     
n.速度( velocity的名词复数 );高速,快速
  • In experimenting we find out that sound travels with different velocities through different substances. 在实验中,我们发现声音以不同的速度通过不同的物质而传播。 来自《现代汉英综合大词典》
  • A gas in thermal equilibrium has particles of all velocities. 处于热平衡的气体,其粒子有一切速度。 来自辞典例句
3 resonance hBazC     
  • Playing the piano sets up resonance in those glass ornaments.一弹钢琴那些玻璃饰物就会产生共振。
  • The areas under the two resonance envelopes are unequal.两个共振峰下面的面积是不相等的。
4 diagnosis GvPxC     
  • His symptoms gave no obvious pointer to a possible diagnosis.他的症状无法作出明确的诊断。
  • The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做一次彻底的调查分析。
5 assessment vO7yu     
  • This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
  • What is your assessment of the situation?你对时局的看法如何?
6 consultant 2v0zp3     
  • He is a consultant on law affairs to the mayor.他是市长的一个法律顾问。
  • Originally,Gar had agreed to come up as a consultant.原来,加尔只答应来充当我们的顾问。
7 wringing 70c74d76c2d55027ff25f12f2ab350a9     
  • He was wringing wet after working in the field in the hot sun. 烈日下在田里干活使他汗流满面。
  • He is wringing out the water from his swimming trunks. 他正在把游泳裤中的水绞出来。
8 rotation LXmxE     
  • Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
  • The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。
9 contraction sn6yO     
  • The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
  • The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。
10 relaxation MVmxj     
  • The minister has consistently opposed any relaxation in the law.部长一向反对法律上的任何放宽。
  • She listens to classical music for relaxation.她听古典音乐放松。
11 timing rgUzGC     
  • The timing of the meeting is not convenient.会议的时间安排不合适。
  • The timing of our statement is very opportune.我们发表声明选择的时机很恰当。
12 optimally 8f28d1e19f055043f464b21c2332a5a4     
  • In the classic script for a Cartel, the group sets a unified optimally exploiting price structure. 按照卡特尔的传统范本,这个集团制定出一个统一的最有利于剥削的价格结构。 来自辞典例句
  • RF power LDMOS with a trench drift region is optimally designed. 对射频功率LDMOS槽形漂移区的结构进行了优化设计。 来自互联网
13 complement ZbTyZ     
  • The two suggestions complement each other.这两条建议相互补充。
  • They oppose each other also complement each other.它们相辅相成。
14 apex mwrzX     
  • He reached the apex of power in the early 1930s.他在三十年代初达到了权力的顶峰。
  • His election to the presidency was the apex of his career.当选总统是他一生事业的顶峰。
15 velocity rLYzx     
  • Einstein's theory links energy with mass and velocity of light.爱因斯坦的理论把能量同质量和光速联系起来。
  • The velocity of light is about 300000 kilometres per second.光速约为每秒300000公里。
TAG标签: heart age gender motion imaging