斑点追踪评价正常成人右室长轴心肌形变能力

Assessment of right ventricular free wall longitudinal myocardium deformation using speckle tracking imaging in normal subjects

目的应用斑点追踪技术定量分析正常成人右室局域心肌形变能力,并探讨年龄对形变能力的影响。方法应用斑点追踪成像技术测量75例健康成人的右室游离壁各节段心肌应变及应变率,在二维应变的模式下于心尖四腔观上勾画右室心内膜面,测量并记录右室游离壁基底段、中段及心尖段收缩期峰值应变(ε)、收缩期峰值应变率(SRs)、舒张早期峰值应变率(SRe)、舒张晚期峰值应变率(SRa)及舒张早期峰值应变率与舒张晚期峰值应变率的比值(SRe/SRa),比较各节段间变化规律及各指标随年龄增加的变化规律。结果右室基底段ε、SRs、SRe、SRa显著高于心尖段,SRs、SRe高于中段,SRe/SRa各节段间无差异。SRe随年龄增长而轻度减低,与年龄呈负相关(r=-0.229～-0.301,P<0.05),SRa随年龄增长而增加,与年龄呈显著正相关(r=0.438～0.525,P<0.01),SRe/SRa随年龄增长而明显减低,与年龄呈显著负相关(r=-0.466～-0.614,P<0.01)。结论斑点追踪技术可以准确、客观的评估右室长轴心肌收缩期、舒张期形变的能力。右室舒张期形变能力随年龄增加而减低。

Objective To assess right ventricular free wall longitudinal myocardium deformation and study the changes with normal aging by speckle tracking imaging（STI）.Methods Peak myocardial systolic strain（ε）,strain rate（SRs）,early diastolic strain rate（SRe）,late diastolic strain rate（SRa）,the ratio of SRe/SRa were measured respectively in right ventricular free wall basal,mid and apical segment in 75 healthy volunteers（age range：21-71 years）by STI from the apical 4-chamber view.Results RV longitudinal strain and strain rate were the highest in the basal segment of the free wal1.Older subjects had lower early diastolic strain rate（SRe）than younger subjects,but had higher late diastolic strain rate（SRa）.A negative correlation between age and the ratio of SRe/SRa was shown for all RV free wall segments（r=-0.466--0.614,P〈0.01）.Conclusion STI is useful for studying RV myocardium deformation.RV diastolic strain rate shows age-related changes.