定量组织速度成像技术评价正常成人右心室局域心肌功能

Evaluation of the regional right ventricular myocardium function by quantitative tissue velocity imaging in normal subjects

目的评价健康成人的右心室局域心肌功能,并探讨正常增龄对其功能的影响。方法应用定量组织速度成像技术测量76例健康成人的右室局域心肌长轴功能。于心尖四腔观上将取样点分别置于右室游离壁基底段、中段和心尖段心肌的中点,记录并测量在等容收缩期、收缩期、等容舒张期、舒张早期和舒张晚期心肌运动的峰值速度(Vic,Vs,Vir,Ve,Va)、收缩期达峰时间(TQ-S)和Ve/Va值等;同时观察各测量指标随年龄增加的变化规律。结果右心室肌在长轴方向上呈现较强的收缩和舒张运动,峰值运动速度由心底至心尖方向逐渐递减(P<0.05~0.01)。右室各节段心肌的Vic、Vs测值随年龄增加并无明显变化(r=-0.01^-0.04,P>0.05);而TQ-S随年龄增加相应延长,与年龄显示较好的正相关(r=0.39~0.55,P<0.05~0.01);Vir测值随正常增龄无明显变化(P>0.05),而Ve随年龄增加而降低,并伴有Va的相应增加;这些变化在基底节段尤为明显。Ve/Va值则呈现随年龄增加而降低的趋势。结论定量组织速度成像技术可准确、客观地反映右心室局域心肌纤维的收缩和舒张特性。临床在评价右室心肌功能,尤其是舒张功能时,应充分考虑心肌老化因素的影响。

Objective To assess regional right ventricular （RV） myocardium function and study the changes with normal aging by quantitative tissue velocity imaging （QTVI）. Methods RV myocardium longitudinal systolic and diastolic function were measured in 76 healthy volunteers （age range： 21-81years） by QTVI. The sample volumes were separately located at RV free wall and at three levels （basal,middle and apical） ; the peak myocardial velocity in isovolumetric period, systolic period, diastolic period （Vic, Vs, Vir, Ve, Va ）, the time interval of the onset of Q wave on electrocardiogram and the peak of systolic wave （TQ-S）, the ratio of Ve and Va were separately measured. Results RV free wall showed the strong contraction and relaxation in the velocity map. There was a velocity gradient along the RV free wall. The velocity values of apical segments were higher than those of the mid and basal segments （P 〈 0. 05-0. 01）. Normal aging brought degeneration in early diastolic velocities and a corresponding increased in atrial contraction velocities. These results were mostly marked at the basal segment. In contrasts, systolic myocardium velocities （Vic ,Vs） were stable with aging. Conclusions QTVI may prove useful for studying the contractile and elastic properties of RV myocardium. The age-related changes of RV myocardium should be fully taken into consideration when assessing RV diastolic function.