斑点追踪成像评价无心肌肥厚高血压病人左心室功能

SPECKLE TRACKING IMAGING IN ASSESSMENT OF LEFT VENTRICULAR FUNCTION IN HYPERTENSIVE PATIENTS WITHOUT MYOCARDIAL HYPERTROPHY

目的 应用斑点追踪成像技术（STI）评价无心肌肥厚的原发性高血压病人早期左心室心肌的功能。方法 选取左心室充盈正常的高血压病人40例（Ⅱ组）、左心室松弛性减低的高血压病人40例（Ⅲ组）、健康对照者30例（对照组）、应用STI分别测量各组左心室长轴切面、心尖四腔心切面、两腔心切面整体心肌和心内膜下心肌二尖瓣水平、乳头肌水平、心尖水平收缩期长轴应变，通过左心室短轴心底水平和心尖水平分别计算扭转角度峰值（Ptw）、收缩末期扭转角度（AVCtw）、等容舒张末期扭转角度（MVOtw）、扭转速度达峰时间（PTV）、解旋速度峰值（PUV）、等容解扭转率（UntwR）、解旋减半时间（UHT）等左心室扭转-解旋参数。结果 与对照组比较，Ⅱ组基底段、中间段、心尖段心内膜下心肌收缩期峰值应变减低，Ptw、AVCtw、MVOtw、PTV、PUV增加，UntwR减低，UHT延长,差异均有显著性（F=3.34-23.75，q=1.69-13.51，P〈0.05）；Ⅲ组基底段、中间段、心尖段的心内膜下心肌收缩期峰值应变减低，差异有显著性（F=9.13-11.91，q=2.94-3.64，P〈0.01）。Ⅲ组与Ⅱ组比较，基底段、中间段、心尖段的整体心肌收缩期峰值应变减低，UntwR减低，差异有显著意义（q=3.12-3.59,P〈0.05）。结论 STI可用于评价原发性高血压病人左心室心肌功能的早期受损情况。

Objective To evaluate the left ventricular myocardial function （LVMF） of hypertensive patients without myocardial hypertrophy by using speckle tracking imaging （STI）. Methods Forty hypertensive patients with normal left ventricular filling （group A）,40 with abnormal left ventricular relaxation （group B） and 30 normal controls （group NC） were studied. Using STI, the global peak systolic longitudinal strain rate during atrial systole of whole-layer myocardium and sub-endocardium （including the levels of mitral annulus, papillary muscle and apex） at long-axis of left ventricle views, apical 4-chamber views and apical 2-chamber views were measured. Twist at aortic valve closure,twist at mitral valve opening, peak of twist velocity, peak of untwist velocity, untwisting rate and twisting half-time of left ventricular short-axis views at the levels of mitral valve and apex were calculated. Results Compared with group NC, the findings in group A were that the peak systolic strain in basal, middle and apical segments of subendocardial myocardium reduced, Ptw, AVCtw, MVOtw, PTV and PUV increased, UntwR decreased, and HTU extended, the differences were significant （F=3.34-23.75,q=1.69-13.51,P〈0.05）, the findings in group B were that the peak systolic strain in basal, middle and apical segments of subendocardial myocardium reduced （F=9.13-11.91,q=2.92-3.64,P〈0.05）. A comparison between groups B and A showed the peak systolic strain in basal, middle and apical segments of subendocardial myocardium and UntwR in group B decreased （q=3.12-3.59,P〈0.05）. Conclusion Speckle tracking imaging can be used to assess the early damage of left ventricular myocardium in patients with essential hypertension.