左心房容积追踪技术评价正常成年人左心房容积及功能变化的研究

目的应用左心房容积追踪技术(LAVT)评价不同年龄段正常成年人左心房容积和功能变化情况。方法将90例健康成年受试者按年龄分为6组:A组(18²9岁),B组(3029岁),B组(30³9岁),C组(4039岁),C组(40⁴9岁),D组(5049岁),D组(50⁵9岁),E组(6059岁),E组(60⁶9岁),F组(7069岁),F组(70⁷9岁)。采集并存储心尖四腔心及心尖两腔心切面各连续3个心动周期动态二维图像,于收缩末期手动描记左心房心内膜面,启动左心房容积追踪技术自动得到双平面左心房容积变化曲线及左心房容积变化速率曲线,并分别记录左心房最大容积(LAVmax)、心电图P波对应左心房容积(LAVp)、左心房最小容积(LAVmin),收缩期左心房充盈速率峰值(dv/dtS)、舒张早期左心房排空速率峰值(dv/dtE)、舒张晚期左心房排空速率峰值(dv/dtA),并将容积指标用体表面积(BSA)标化(LAVImax、LAVIp、LAVImin),计算左心房总体排空率、被动排空率及主动排空率(%LAVI total、%LAVIpass、%LAVIactive);同时记录二尖瓣口血流E峰、A峰,二尖瓣环左心室侧壁处组织多普勒(TDI)e峰、a峰,并分别计算E/A、e/a及E/e比值。结果 6组间%LAVIpass、dv/dtE随年龄增长大致呈下降趋势,差异有统计学意义(P<0.05);而LAVImax、LAVImin、LAVIp、dv/dtA、%LAVIact值则随年龄增长大致呈增加趋势,差异有统计学意义(P<0.05);LAEF、dv/dtS随年龄变化不明显,差异无统计学意义(P>0.05)。结论 LAVT技术是一种定量评价左心房容积及功能变化的新技术,能够较为准确地反应不同年龄阶段正常成年人左心房的容积及功能变化情况,LAVT各参数指标结合二尖瓣口血流可以较为准确地反映左心舒张功能的情况,从而为临床评价左心室舒张功能改变提供新的参考依据。

Study on the left atrial volume and functions in normal adults by LAVT

Objective Using Left Atrial Volume Tracking （LAVT） to evaluate the change of left atrial volume and functions in normal adults of different stages. Methods 90 healthy adults aging from 18-79 years old were divided into 6 groups： group A（18-29 years old）, group B（30-39 yeas old）, group C（40-49 years old）, group D（50-59 years old）, group E（60-69 years old）, group F（70-79 years old）. Acquire the apical four chamber view and apical two chamber view imagings, and store 3 continuous cardiac cycle of imaging. Tracking the left atrial endocardial surface manually at the end-systolic stage, then starting LAVT automatically, the left atrial volume curves and left atrial volume changing rate curves in biplane were obtained, and recorded the maximum left atrial volume（LAVmax）, left atrial volume at P wave of electrocardiogram（LAVp）, the minimum left atrial volume（LAVmin）, peak filling rate of left atrial in systolic（dv/dtS）, peak emptying rate of left atrial in early diastolic（dv/dtE）, peak emptying rate of left atrial in late diastolic（dv/dtA）, and the body surface area（all the volume indexes were standard by the BSA, recorded as LAVImax, LAVIp, LAVImin）. Left atrial emptying rate, passive emptying rate and active emptying rate（%LAVItotal, %LAVIpass, %LAVIactive） were also calculated; and mitral valve E peak, A peak, lateral wall of mitral valve ring TDI（Tissue Doppler Imaging） e peak, a peak were recorded and the E/A ratio, e/a ratio, E/e ratio were calculated. Results Among the 6 groups, %LAVIpass and dv/dtE generally decreased with age increasing and there were significant statistically differences（P＆lt;0.05）;while the LAVImax, LAVImin, LAVIp, dv/dtA,%LAVIact values increased with age increasing and there were significant statistically difference（P＆lt;0.05）; dv/dtS and LAEF did not change significantly with age increasing, and there were no statistically difference（P＆gt;0.05）. Conclusions LAVT is a new technique for quantitative assessment of left atrial volume and function, it can accurately evaluate changes of left atrial volume and functions in different ages of normal heathy adults, the parameters of LAVT combined with mitral valve flows can reflect the left ventricular diastolic function more accurately, and provide a new method to evaluate left ventricular diastolic functions.