速度向量成像评价Valsalva动作对正常人左室扭转的影响  

Effects of the Valsalva Maneuver on Left Ventricular Twist in Healthy Subjects by Velocity Vector Imaging

作　　者：张昌云 陈小龙[2] 丁鹏 张小用[2] 曹铁生[3] 

机构地区：[1]渭南市中心医院功能科,陕西渭南714000 [2]陕西省人民医院影像中心,陕西西安710068 [3]第四军医大学唐都医院超声科,陕西西安710038

出　　处：《现代生物医学进展》2012年第32期6263-6266,共4页Progress in Modern Biomedicine

基　　金：国家自然科学基金(81171348)

摘　　要：目的:应用速度向量成像(VVI)技术评价Valsalva动作对正常人左室扭转运动的影响,探讨其机理及临床意义。方法:应用VVI技术对30例正常人初始时与40 mmHg乏氏动作张力期10s时左室短轴心内膜及心外膜下心肌旋转(ROT)、扭转(TW)及扭矩(TOR)进行定量分析。结果:与初始时比较,40 mmHgValsalva动作张力期10s时左室舒张末容积(LVEDV)、收缩末容积(LVESV)及每搏量(SV)减低(P<0.001)而心率增快(P<0.001),射血分值(EF)没有变化(P>0.05);左室心尖部心内膜及心外膜下心肌收缩期峰值旋转均减低(P<0.05),而基底部ROT无明显变化(P>0.05),导致左室TW减低(P<0.05)而TOR没有变化(P>0.05)。结论:40 mmHg Valsalva动作可影响正常人左室ROT及TW。临床上Valsalva动作应尽量减少负荷压及持续时间,避免其对心脏功能的不利影响。Objective： To investigate the effect of the Valsalva maneuver （VM） on lefl ventricular （LV） twist in healthy subjects and to study its mechanics and the potential clinical implication. Methods： Thirty healthy volunteers were recruited to undertake VM at a load of 40 mmHg for 10 s. LV rotation （ROT）, twist （TW） and torsion （TOR） in both endocardium （Endo） and epicardium （Epi） were studied at rest and at the end of strain phase of VM, using velocity vector imaging. Results： Compared with values taken at rest, at the end of strain phase of VM： LV end-diastolic volume （LVEDV）, LV end-systolic volume （LVESV） and stroke volume （SV） dramatically de- creased （P〈0.001） while heart rate （HR） dramatically increased （P〈0.001）, and ejection fraction （EF） did not change （P〉0.05）; Apical ROT significantly decreased （P〈0.05） while basal ROT did not change （P〉0.05）. Consequently, LV TW significantly decreased （P〈0.05）. Conclusions： The 40 mmHg VM has significant influence on LV ROT and TW, which is mainly induced by a decreased apical ROT. These results suggest that 40 mmHg VM can affect LV function in healthy subjects by means of decreasing LV ROT and TW. Maybe VM ought to be performed clinically at lower loads and for shorter strain times, in order to prevent its adverse effects as far as possible.

关 键 词：超声心动图法 VALSALVA动作 心室扭转 左心室扭转 速度向量成像 

分 类 号：R445[医药卫生—影像医学与核医学]