定量组织速度成像技术评价左室肥厚大白兔左室舒张功能

目的探讨定量组织速度成像技术评价大白兔左室肥厚模型左室舒张功能的可行性.方法 40只大白兔分别给予假手术、主动脉缩窄和主动脉缩窄 血管紧张素受体拮抗剂干预,于术后4周和8周应用传统的超声心动图方法和定量组织速度成像(QTVI)技术检测不同处理家兔的心脏,测量常用心功能参数,于心尖四腔切面记录二尖瓣口血流频谱,记录心尖四腔切面的定量组织速度成像图像,脱机分析左室侧壁所对应的二尖瓣瓣环处的舒张早期峰值速度(Ve)和左房收缩期峰值速度(Va),并计算Ve/Va.结果左室肥厚组实验8周时,室壁增厚,左室舒张末内径增大,左室心肌重量增加,与假手术组同期和本组4周相比均有显著性差异(P<0.05).伊贝沙坦组实验8周时左室心肌重量与左室肥厚组相比有显著性差异(P<0.05).左室肥厚组Ve/Va与假手术组相比有显著性差异(P<0.05).伊贝沙坦组Ve/Va与左室肥厚组相比有显著性差异(P<0.05),与假手术组比较无差异.结论定量组织速度成像技术能够定量评价大白兔左室舒张功能,比传统方法提供更多的信息.

Assessment of Left Ventricular Diastolic Function in Rabbit with Left Ventricular Hypertrophy by Quantitative Tissue Velocity Imaging

Objective To probe the feasibility of the assessment of left ventricular diastolic function in rabbit with left ventricular hypertrophy by quantitative tissue velocity imaging(QTVI).Methods 28 rabbits with LV hypertrophy due to banding of the ascending aorta(LVH) and 10 age-matched sham-operated rabbits were involved in our study,LVH rabbits were randomized to no treatment(n=14) or treatment with angiotensin receptor antagonist irbesartan((30 mg/kg) per day,n=14).4 weeks and 8 weeks after aortic banding,M-mode echocardiograms and transmitral Doppler spectra and QTVI image of 4-chamber view at cardiacapex were recorded.The left ventricular wall thickness and the left ventricular end-diastolic diameter were measured through M-mode echocardiography,LV mass was calculated.The peak velocities of early diastole(Ve) and artrial contraction(Va) of the mitral annular from lateral wall were measured by QTVI,and Ve/Va was calculated.Results At 8 week the left ventricular wall thickness and the left ventricular end-diastolic diameter and LV mass of LVH rabbits increased more than that of sham-operated rabbits significantly(P<(0.05)).LV mass of irbesartan rabbits was lower than that of LVH rabbits significantly(P<(0.05)).The Ve/Va of LVH rabbits was less than 1,there was significant difference between LVH rabbits and sham-operated rabbits(P<(0.05)) and irbesartan rabbits respectively(P<(0.05)).Conclusion QTVI could assess left ventricular diastolic function in rabbit with left ventricular hypertrophy quantitatively and it offered more information than routine echocardiography.