组织多普勒径向应变率的理解误区及其局限性

Misunderstanding and clinical limitation of radial strain rate imaging based on tissue Doppler imaging

目的明确组织多普勒成像技术(TDI)的径向应变率(SR)与心肌速度梯度(MVG)的异同,分析左心室径向SR在临床应用的局限。方法检索有关SR及MVG的资料。获取30例健康志愿者(正常组)及30例原发性高血压患者(高血压组)左心室短轴前室间隔及左心室后壁径向SR曲线。比较两组左心室后壁收缩期(SRs)及舒张早期(SRe)峰值径向SR的差异。分别采用应变长度(SL)为12mm及8mm,测量正常组左心室后壁SRs及SRe峰值径向SR。结果正常组左心室后壁的径向SR曲线比较规律,而前室间隔的径向SR曲线比较杂乱。正常组左心室后壁SRe明显大于SRs(5.21±0.94)1/s vs(2.08±0.31)1/s(P<0.05)。高血压组左心室后壁径向SRs及SRe均低于正常组(1.13±0.29)1/s vs(2.08±0.31)1/s、(2.45±0.52)1/s vs(5.21±0.94)1/s(P<0.05)。正常组SL=12mm时的SRs略大于SL=8mm时的测值但差异无统计学意义(1.83±0.27)1/s vs(2.08±0.31)1/s(P>0.05);而SL=12mm的SRe明显大于SL=8mm时的测值(4.29±0.70)1/s vs(5.21±0.94)1/s(P<0.05)。结论组织多普勒径向SR并不完全等同于MVG,在评价左心室短轴局部心功能时有一定的局限性。

Objective To differentiate radial strain rate（SR） based on tissue Doppler imaging from myocardium velocity gradient（MVG） and understand its limitations in clinical application.Methods Literatures about radial SR and MVG were searched.Quantitative tissue Doppler imaging（QANALYS） studies were performed in mid short-axis view in 31 healthy subjects and 30 essential hypertension with hypertrophic myocardium.Systolic SR（SRs） and early diastolic SR（SRe） measurements were made of the radial motion from interventricular septum and posterior wall.The radial function of essential hypertension in posterior wall with normal controls was compared.SRs and SRe of the posterior wall were measured in different strain length（SL）,12 mm or 8 mm in normal controls.Results The curve of SR in interventricular septum was irregular and complex.The SRe of posterior was higher than SRs in normal controls（5.21±0.94） 1/s vs（2.08±0.31） 1/s（P〈0.05）.SRs and SRe of posterior on parasternal short axis view were significantly smaller in essential hypertension patients than those in normal controls（1.13±0.29） 1/s vs（2.08±0.31） 1/s,（2.45±0.52） 1/s vs（5.21±0.94） 1/s（P〈0.05）.SRs with SL of 12 mm was slightly higher than that with SL of 8 mm（1.83±0.27） 1/s vs（2.08±0.31） 1/s（P〉0.05）.While SRe with SL of 12 mm was significantly higher than that with SL of 8 mm（4.29±0.70） 1/s vs（5.21±0.94） 1/s（P〈0.05）.Conclusion Radial SR based on tissue Doppler imaging was not identical to MVG.Radial SR has some limitations in assessing the function of left ventricle.