斑点追踪技术评价无左心室肥厚高血压患者左心室扭转与解旋运动

目的探讨无左心室肥厚高血压患者左心室扭转与解旋运动的特点。方法入选无左心室肥厚的高血压患者85例及健康对照者40名,应用超声二维斑点追踪技术(2D-STI)测量并计算短轴心尖部旋转峰值(PAR)及达峰时间、基底部旋转角度峰值(PBR)及达峰时间、左心室整体扭转角度峰值(Ptw)及达峰时间,收缩末期扭转角度(AVCtw)、等容舒张末期扭转角度(MVOtw)、解旋减半时间(HTU)、解旋率。结果高血压组PAR、Ptw、AVCtw、MVOtw高于对照组[(10.55±4.14)°比(8.95±3.46)°,(18.18±4.58)°比(16.33±4.50)°,(17.11±4.82)°比(14.95±4.61)°,(14.33±4.43)°比(12.40±4.86)°,均P<0.05],解旋率低于对照组[(36.06±15.98)%/ms比(48.96±21.16)%/ms,P<0.05]。Ptw与PAR呈正相关,与PBR呈负相关(分别r=0.825,-0.474,均P<0.05);Ptw与LVMI呈正相关(r=0.208,P<0.05),解旋率与左心室质量指数(LVMI)呈负相关(r=-0.231,P<0.05)。结论高血压患者左心室扭转及解旋运动的异常早于室壁厚度的增加,2D-STI技术可定量检测左心室扭转与解旋运动,有可能作为评价高血压患者左心室收缩及舒张功能的早期指标。     

速度向量成像技术评估高血压病患者左室扭转运动的价值

目的:探讨速度向量成像(velocity vector imaging,VVI)技术评价高血压病患者左室扭转运动的临床价值。方法: 应用彩色多普勒超声对28例正常人和68例原发性高血压患者,于胸骨旁左室心底部、心尖部经胸采集并存贮左室短轴二维图像,根据Ganau分类法,将原发性高血压患者分为3组:左室正常构型组（20例）、向心性肥厚型组（23例）和离心性肥厚型组（25例）。应用VVI 脱机分析软件测量行脱机分析,计算并记录心底部旋转角度峰值(PBr),心尖部旋转角度峰值(PAr),左室扭转角度峰值(Ptw),解旋速度峰值(PutwV),解旋速度达峰时间(TPKutw)、等容舒张期解旋百分比(Iutw％)。结果: ①与对照组相比,高血压病组左室PutwV增大,TPKutw延迟,Iutw％下降（P<0.05）,高血压病各组间PutwV、TPKutw 、Iutw％差异无统计学意义;正常构型组、向心性肥厚型组的Ptw明显增大（P<0.05,P<0.01）,离心性肥厚型组Ptw下降（P<0.01）,高血压病各组间Ptw差异有统计学意义（P<0.05,P<0.01）。②Ptw与左室射血分数（LVEF）呈正相关(r=0.65,P<0.05)。结论: VVI技术可以准确测量心室扭转角度,能从心肌解剖力学角度早期敏感评估高血压病患者的心功能变化。     

二维超声斑点追踪显像技术对正常人左室旋转和扭转运动的评价

目的:应用二维超声斑点追踪显像技术探讨正常人左室旋转(LVrot)和左室扭转(LVtw)运动特征。方法:入选健康成人志愿者58例,取胸骨旁左室心尖和心底短轴观对LVrot进行定量分析,获LVrot及LVtw角度随心动周期变化曲线,记录心底部与心尖部LVrot角度峰值和LVtw角度峰值及达峰时间。结果:正常人扭转运动主要表现为心底部顺时针旋转和心尖部逆时针旋转,心脏整体表现为心动周期内逆时针方向为主的扭转运动。心尖部和心底部旋转角度达峰时间差异无统计学意义(P>0.05)。扭转角度于收缩末期达峰值。结论:应用二维超声斑点追踪显像技术可无创性评价正常人LVrot和LVtw运动特征。左室心底部及心尖部旋转角度、达峰时间可做为评价左室运动同步性指标之一。     

超声斑点追踪技术在评价心肌梗死患者左室径向收缩功能中的应用

目的探讨超声斑点追踪技术（STI）诊断节段性室壁运动异常及评价左室收缩功能的临床应用价值。方法对30例心肌梗死患者（心梗组）和30例查体健康者（对照组）应用超声心动图仪获得高频帧二维图像,使用二维应变软件检测左室短轴三个水平（二尖瓣、乳头肌、心尖）各节段心肌的峰值径向应变（SR）及应变率（SRs）。结果心梗组梗死节段峰值SR和SRs在乳头肌水平各节段心肌均显著低于对照组（P均〈0.01）,而二尖瓣水平、心尖水平只有前间隔、前壁、侧壁、后间隔不同程度低于对照组（P〈0.05）,三个水平节段心肌与对照组比较均有显著性差异（P〈0.01）,SRs、SR均与LVEF明显相关（r分别=0.608、0.375,P分别〈0.01、0.05）。结论 STI能准确评价节段性室壁运动异常,可作为临床评价心肌梗死患者左室收缩功能的一种更科学、更客观的方法。     

斑点追踪显像联合Logistic回归评价慢性肺心病患者左心室扭转的改变

目的 应用Logistic回归筛选超声二维斑点追踪显像技术(STI)检测慢性肺心病患者左心室旋转/扭转改变的敏感指标,并探讨其评价慢性肺心病患者左心室功能异常的临床价值. 方法 选取36例慢性肺心病患者(慢性肺心病组)和38例健康体检者(对照组),采集胸骨旁二尖瓣口水平及心尖水平短轴切面图像,应用Echo PAC软件测定心底旋转峰值、心尖旋转峰值、左室扭转峰值、收缩末期心底旋转值、收缩末期心尖旋转值、收缩末期左室扭转值,应用Logistic回归对左室旋转/扭转的相关指标进行分析筛选,并建立回归方程,应用受试者工作特征(ROC)曲线明确以扭转特异参数(左室扭转峰值、收缩末期左室扭转值)判定左室功能减退的最佳诊断界值. 结果 与对照组比较,慢性肺心病组左心室旋转/扭转各特异参数降低(均P＜0.01).Logistic回归分析结果显示,收缩末期左心室扭转值和左室扭转峰值与慢性肺心病患病有关(OR=0.473、0.706,P=0.007、0.011).ROC曲线示以左心室扭转峰值判定左室功能减退的曲线下面积为0.819(95％CI:0.683～0.956),临界值为12.070°,灵敏度84.6％,特异度73.9％;以收缩末期左室扭转值判定左室功能减退的曲线下面积为0.875(95％ CI:0.744～1.000),临界值为10.680°,灵敏度84.6％,特异度91.3％.结论 STI技术能敏感地检测慢性肺心病患者左室心肌扭转的改变,并评估其左心室功能的状态.     

慢性心力衰竭患者左室扭转和N端B型利钠肽原的相关性研究

目的分析慢性心力衰竭患者左室扭转与N端B型利钠肽原（NT—proBNP）之间的关系,探讨左室扭转诊断慢性心力衰竭的应用价值。方法应用二维斑点追踪成像技术评价102例慢性心力衰竭患者和41名健康人左室旋转和左室扭转峰值角度及相应达峰时间,分析上述指标与血浆NT—proBNP水平之间的关系。结果①与对照组比较,慢性心力衰竭患者左室旋转（心尖位和心底位）和左室扭转峰值角度均显著减小,左室旋转和左室扭转相应达峰时问则均显著延长,而NT—proBNP水平明显增高（P〈0．01）。②直线相关分析显示,慢性心力衰竭患者NT—proBNP水平与年龄、心尖位旋转达峰时间和左室扭转达峰时间呈正相关,与心尖位旋转峰值和左室扭转峰值呈负相关。③多重逐步线性回归分析将年龄等危险因素调整后表明,慢性心力衰竭患者NT—proBNP水平同左室心尖位旋转峰值和左室扭转峰值具有独立负相关关系。结论慢性心力衰竭患者左室旋转和扭转运动减低;其NT—proBNP水平与左室心尖位旋转峰值和左室扭转峰值呈负相关。     

速度向量成像技术评价心脏再同步化治疗左室扭转与收缩同步性的关系

目的应用速度向量成像技术(VVI)探讨心脏再同步化治疗(CRT)患者左室扭转参数与收缩同步性的关系。方法选取慢性心力衰竭(简称心衰)行CRT患者,分别于术前,术后1、4个月采集患者左室短轴切面(二尖瓣水平、乳头肌水平、心尖水平)及心尖四腔心、两腔心和长轴切面的二维高帧频图像,运用Siemens Syngo WorkPlace软件测量不同短轴切面心底、心尖的旋转角度,最后计算左室扭转角度;观察不同时间点的QRS波时限、左室壁12节段达峰时间标准差(Ts-12-SD)、跨主动脉瓣血流时间速度积分(AVTI)、左室舒张末内径(LVEDV)、左室收缩末内径(LVESV)、左室射血分数(LVEF)及NYHA心功能分级、6 min步行距离(6MWT)和明尼苏达心衰生活质量评分。结果 30例患者成功完成11例CRT-P,19例CRT-D植入手术。术后LVEDV、LVESV、生活质量评分改善,QRS波变窄(P0.001);LVEF、AVTI、6 MWT增加(P0.001)。术后1、4个月时收缩期左室心尖部旋转角度峰值(PAr)、左室心底部旋转角度峰值(PBr)、左室扭转角度峰值(Ptw)较术前增大,差异均有显著性(P0.01)。双变量Pearson直线相关分析结果显示,术前,术后1、4个月时Ptw(SM)和Ts-12-SD呈正相关性(分别为r=0.385、0.435、0.422,P均0.05);与LVEF呈正相关性(分别为r=0.375、0.411、0.37,P均0.05)。术前Ptw和术后1、4个月时的LVEF也呈正相关性(分别为r=0.379、0.375,P均0.05)。而术前、术后1、4个月时的Ptw(SM)和Ts-12-SD与QRS波时限均无直线相关关系(P0.05)。结论左心室扭转指标可准确评价左室的收缩同步性,可能为临床提供一种除Ts-12-SD外简便的新型评估方法。     

多普勒超声心动图评价急性心肌梗塞后左室重构及心功能改变

应用多普勒超声心动图对56例不同部位急性心肌梗塞（AMI）后患者及40例正常人左室结构（LVR）、收缩舒张功能参数进行对比分析研究。结果显示AMI后患者左室舒张及收缩末期内径、左心室舒张末期容积、左心室收缩末期容积、左室射血前期与射血时间比、舒张晚期峰值血流速度、A峰面积增大；射血分数、短轴缩短率、舒张早期峰值血流速度、E峰／A峰面积则降低，两组间比较有极显著性差异（P＜0．01）。认为AMI后患者心脏不同程度的发生了LVR及收缩舒张功能减退。     

三维斑点追踪成像评价不同病变血管的冠心病患者左心室扭转运动

目的 应用三维斑点追踪成像(three-dimensional speckle tracking imaging,3D-STI)技术评价不同病变血管的冠心病患者左心室心肌扭转运动。方法 220例研究对象依冠状动脉血管将患者分为正常组、前降支病变组(LAD组)、回旋支病变组(Lcx组)、右冠状动脉病变组(RCA组),应用三维斑点追踪成像技术获得心尖段、基底段、左室整体扭转角度峰值(PAR、PBR、Ptw)及达峰时间(PART、PBRT、PtwT)、左室射血分数(LVEF)等指标,比较各组与正常组之间上述指标的差异。结果 LAD组PART、 PtwT较对照组延长,PAR、Ptw较对照组减低,差异有统计学意义(P<0．05)；LCX组、RCA组的PBRT较对照组延长,而扭转参数与对照组比较差异无统计学意义(P>0.05)；与对照组比较,多支病变组PART、 PBRT、 PtwT延长,PAR、PBR、Ptw较对照组减低；冠心病组扭转角度峰值与LVEF均有一定相关性,PAT与LVEF相关性最佳(r=0.61,P<0.05)。结论 3D-STI可以检测不同病变血管的冠心病患者左心室扭转运动,不同的冠状动脉血管的冠心病患者左心室扭转运动有所不同。     

左心室旋转运动与收缩功能相关性的临床研究

目的 分析左心室乳头肌水平旋转角度与左室射血分数（LVEF）、左室短轴缩短率（FS）、MAM位移的相关性,探讨其在左室功能评价中的临床价值。 方法 研究对象89例,其中左室收缩功能减退（LVEF <50%）39例,左室收缩正常（LVEF >50%）50例。M型超声心动图测量左室短轴缩短率（FS）、MAM位移;Simpson’s法测量左室射血分数（LVEF）;二维灰阶超声心动图测量左室乳头肌水平旋转角度。 结果 89例研究对象心脏收缩时旋转角度为2.0～13.4度,平均旋转角度（7.73±3.76）度;左室收缩功能减退组较左室收缩正常组LVEF、FS、MAM位移、左室乳头肌水平旋转角度显著减小（P ＜0.001）;左室乳头肌水平旋转角度与LVEF、FS、MAM位移显著正相关（P＜0.001）。 结论 左室乳头肌水平旋转角度可作为评价左室整体收缩功能的一项指标。     

Differences in Left Ventricular Twist Related to Age: Speckle Tracking Echocardiographic Data for Healthy Volunteers from Neonate to Age 70 Years

Objective: To determine normal left ventricular (LV) twist characteristics in different age groups and assess changes between neonates and the elderly. Methods: Short‐axis left ventricle images at basal and apical levels were acquired in 274 healthy volunteers (aged 15 days to 72 years) by two‐dimensional echocardiography, and were analyzed off‐line using Speckle tracking echocardiography (STE) software to obtain LV twist measurements. The peak apical rotation (PAr), peak basal rotation (PBr), peak LV twist (Ptw), peak LV twist normalized by LV length (Ptw N ), peak untwisting velocity (PutwV), and isovolumic untwisting% (Iutw%) were measured. Results: LV twist values vary with age. Ptw was higher in older volunteers. PtwN varied inconsistently with age. PutwV and Iutw% were lower in the young and old with a peak in mid–age ranges. Conclusions: STE is an effective noninvasive method to assess LV twist. Age‐related differences in LV twist may reflect maturation and adaptive modulation of LV torsional biomechanics from neonate to the elderly. (Echocardiography 2010;27:1205‐1210)     

斑点追踪技术对急性心肌梗死心内外膜扭转运动的研究

目的应用二维斑点追踪技术评价急性心肌梗死(AMI)心内外膜及整体的扭转运动变化特点。方法选择初次发生AMI患者56例以及正常对照组35例,应用斑点追踪技术测量左心室收缩期心内膜最大扭转角度(PST-En)、心外膜最大扭转角度(PST-Ep)及整体最大扭转角度(PST-G),对AMI组按照左心室射血分数(LVEF)水平进行分组分析。结果与对照组比较,LVEF≥45%AMI组PST-En和PST-G明显减低,差异有统计学意义(P<0.05),但PST-Ep比较差异无统计学意义(P>0.05),与对照组及LVEF≥45%AMI组比较,LVEF<45%组PST-En、PST-Ep、PST-G均明显减低,差异有统计学意义(P<0.01)。PST-En、PST-Ep、PST-G与左心室舒张末期容积指数(EDVI)、收缩末期容积指数(ESVI)、LVEF呈中度相关(r=-0.60~0.68,P<0.01)。结论在左心功能损害不明显时,心外膜的扭转运动仍发挥代偿作用,在左心室功能明显损害时,心肌各层的扭转运动均明显受损。     

Left ventricular apical rotation is related to ambulatory blood pressure and body mass in healthy elderly females

OBJECTIVE: The interaction between left ventricular (LV) apical rotation, blood pressure (BP) and body mass in elderly females may reveal mechanisms involved in the syndrome of diastolic heart failure. METHODS: Thirty-one healthy females, age 69-84 years, were studied with echocardiography, ambulatory BP and an exercise capacity (VO2peak) test. RESULTS: LV apical short-axis loops were eligible for speckle tracking analysis in 27 subjects. Peak apical rotation (PAR) correlated inversely with diastolic BP (r = -0.47, p = 0.01). PAR correlated positively with stroke volume and body weight (p<0.05), but not with VO2peak (n = 19, p = ns). PAR also correlated with peak rotation velocity in systole (r = 0.76, p<0.0001) and in diastole (r = 0.58, p = 0.001). Diastolic peak rotation velocity correlated with mitral E wave peak velocity (r = 0.48, p = 0.01). There was a significant reduction in LV volumes during the 4 years of follow-up. CONCLUSIONS: In healthy elderly females, there seems to be an interaction between LV apical rotation, BP and body mass. Peak apical rotation and peak diastolic rotation velocity correlate with indices of LV filling and ejection, indicating that suction, a crucial element for effective early LV filling, may be preserved in healthy elderly subjects. Suction deteriorates with elevations of the arterial BP. An age- and BP-related reduction in LV end-diastolic volume may represent an additional impediment to LV filling. Both features may contribute to the development of LV diastolic dysfunction and to episodes of diastolic heart failure.     

二维斑点追踪技术评价心肌梗死患者冠脉 内支架术后左室扭转功能变化

目的 探讨斑点追踪成像技术（STI）在心肌梗死患者冠脉内支架置入术（PCI）疗效评估中的应用价值.方法 选取2011年3月至2013年5月在昆明医科大学第二附属医院心内科接受PCI治疗的心肌梗死患者30例为病例组,正常对照组35例,对正常对照组及接受PCI治疗的患者在术前,术后1周、1个月、3个月、6个月时进行常规超声心动图检查和斑点追踪成像技术分析,测量左室舒张末期内径（LVDd）、左室舒张末期容积（LVESV）、左室收缩末期容积（LVEDV）,以及左室基底段和心尖段收缩期整体旋转角度峰值（Prot-base、Prot-apex）,并计算左心室扭转角度峰值（Ptw）,比较分析各参数在PCI手术前后的变化,结合分析左室扭转功能的改变.结果 与正常对照组比较,病例组PCI治疗前LVDd、LVESV、LVEDV较对照组扩大,LVEF[（43.74±9.47）％比（58.38±4.37）％]较对照组降低,差异均有统计学意义（P均＜0.05）;与PCI治疗前比较,PCI术后1周、1个月LVDd、LVESV、LVEDV及LVEF都没有明显改变,差异无统计学意义（P均＞0.05）;PCI治疗后3个月、6个月时LVDd、LVESV、LVEDV比PCI治疗前有一定缩小,LVEF[（49.33± 11.06）％比（43.74±9.47）％、（53.74±8.06）％比（43.74±9.47）％]增高,差异均有统计学意义（P均＜0.05）.病例组术前Prot base[（-4.57 ±2.16）°比（-8.18±2.67）°]、Prot apex [（5.17±2.25）°比（9.38±2.72）°]、Ptw[（9.74±3.61）°比（17.56±3.41）°]均显著低于正常对照组（P＜0.05）;病例组术后1周Prot base、Prot apex、Ptw均较术前无明显改善（P＞0.05）.病例组术后1、3、6个月Prot base[（-5.84±2.03）°比（-4.57±2.16）°、（-6.68±2.45）°比（-4.57±2.16）°、（-7.56±2.41）°比（-4.57±2.16）°]、Prot apex [（6.58±2.86）°比（5.17±2.25）°、（7.04±3.12）°比（5.17±2.25）°、（8.75±2.63）°比（5.17±2.25）°]、Ptw [（12.42±4.77）°比（9.74±3.61）°、（13.72±     

Reduced and delayed untwisting of the left ventricle in patients with hypertension and left ventricular hypertrophy: a study using two-dimensional speckle tracking imaging.

AIMS: Newly developed two-dimensional ultrasound speckle tracking imaging allows measurements of left ventricular (LV) rotation and twist. Because LV untwisting predominantly occurs during the isovolumic relaxation period, its assessment reflects the process of LV relaxation. The aim of this study was to examine whether LV hypertrophy (LVH) adversely affects LV untwisting and abnormalities in LV untwisting could become a novel marker in assessing LV relaxation abnormalities. METHODS AND RESULTS: We acquired basal and apical LV short-axis images in 49 hypertensive patients. Using two-dimensional strain software, a time-domain speckle tracking was performed, and the mean value of LV rotation was obtained at each plane. LV twist was defined as apical rotation relative to the base. In order to adjust for inter-subject differences in heart rate, the time sequence was normalized to the percentage of systolic and diastolic duration. The degree of LV untwisting was calculated as the percentage of systolic twist : untwisting = (TwistES-Twistt/TwistES) x 100, where Twistt is twist at time t and TwistES is twist at end-systole. Although peak systolic twist was not different, early diastolic LV untwisting and untwisting rate during isovolumic relaxation period was significantly delayed and reduced in parallel to the severity of LVH, as assessed by LV mass index. CONCLUSION: The observed delayed and reduced diastolic untwisting during the isovolumic relaxation period noted in hypertensive patients with LVH may contribute towards the LV relaxation abnormality. Two-dimensional speckle tracking imaging is a novel tool which can be used for the non-invasive assessment of LV relaxation.     

Two‐Dimensional Ultrasound Speckle Tracking Imaging in Evaluation of Early Changes in Left Ventricular Diastolic Function in Patients with Essential Hypertension

Objective: To investigate two‐dimensional ultrasound speckle tracking imaging (STI) in evaluating values of early changes in left ventricular diastolic function in patients with essential hypertension (EH). Methods: Seventy‐five EH patients with left ventricular normal geometry (LVN), including 38 cases with nonleft atrial enlargement (NLAE) and 37 cases with left atrial enlargement (LAE), and 50 healthy persons were enrolled as study participants. Two‐dimensional images of LV apical four‐chamber view, two chamber view, and LV long‐axis view and short‐axis view of mitral annular, papillary muscle, and apical levels were obtained to measure early diastolic E′ peak value, late diastolic A′ peak value, and E′/A′ ratio at LV apical longitudinal strain rate (SrL) and short‐axis radial strain rate (SrR), circumferential strain rate (SrC), and rotation rate (RotR) in all cardiac segments. Average values of E′, A′, and E′/A′ at SrL in three segments on long‐axis and SrR, SrC, and RotR on three short‐axis levels were calculated. Untwisting rate (Untw R) and untwisting half‐time (UHT) were also calculated. Results: (1) Data on 110 of 125 patients were usable for STI analysis. (2) There were no intersegment significant differences between A′ at SrL in three segments or interlevel significant differences between A′ at SrR in three levels in the NLAE group and the LAE group. (3) Compared with the normal group, E′ at SrL and E′/A′ at SrL, SrR and SrC, and Untw R reduced in the NLAE group and the LAE group, while A′ at SrL, SrR, and SrC and E′ at RotR increased and UHT extended. Conclusion: STI may be helpful for the detection of early changes in left ventricular diastolic function in patients with EH. (ECHOCARDIOGRAPHY 2010;27:146‐154)     

Rotational mechanics of the left ventricle in AL amyloidosis

Aims: The aim of this study was to investigate whether alterations in left ventricular (LV) twisting and untwisting motion could be induced by cardiac involvement in patients with immunoglobulin light‐chain (AL) systemic amyloidosis. Methods and Results: Forty‐five patients with AL amyloidosis and 26 control subjects were evaluated. After standard echocardiographic measurement and two‐dimensional (2D) speckle tracking echocardiography, LV rotation at both basal and apical planes, twisting, twisting rate, and longitudinal strain were measured. Tissue Doppler imaging (TDI) derived early diastolic peak velocity at septal mitral annulus (E′) was also evaluated. Twenty‐six of 45 patients with systemic amyloidosis were classified as having cardiac amyloidosis (CA) if the mean value of the LV wall thickness was ≥ 12 mm or not (NCA) if this value was not reached. In NCA patients, both LV twist and untwisting rate were increased while they were decreased in CA patients making them similar to the control group. Longitudinal strain was reduced only in CA patients. Impaired relaxation as indicated by E′ values was progressively reduced in the course of the disease. Conclusions: Both twisting and untwisting motions are increased in patients with AL systemic amyloidosis with no evidence of cardiac involvement while they are reduced in patients with evident amyloidosis cardiac involvement. This finding suggests that impaired LV relaxation induces a compensatory mechanism in the early phase of the disease, which fails in more advanced stage when both twisting and untwisting rates are reduced. The increase in LV rotational mechanics could be a marker of subclinical cardiac involvement. (Echocardiography 2010;27:1061‐1068)     

Effect of mechanical dyssynchrony and cardiac resynchronization therapy on left ventricular rotational mechanics

Alterations in rotational mechanics can bring new aspects to the understanding of left ventricular (LV) dyssynchrony. The aims of this study were to investigate LV rotational mechanics in candidates for cardiac resynchronization therapy (CRT) and to assess the effect of CRT by speckle-tracking echocardiography. Fifty-four patients with heart failure and 33 healthy controls were studied. Thirty-three underwent CRT. Speckle tracking was applied to short- and long-axis views. Radial and longitudinal dyssynchrony were assessed as previously defined. Apical and basal rotations were measured as the average angular displacement about the LV central axis. LV twist and torsion were then calculated. Peak apical and basal rotation, peak LV twist and torsion, apical and basal rotation at aortic valve closure (AVC), and LV twist and torsion at AVC were significantly lower in patients than controls. Apical-basal rotation delay and AVC-to-peak LV twist interval were longer in patients and associated with decreased peak LV twist and LV twist at AVC, respectively. In patients, rotational indexes, particularly LV twist and torsion, were correlated strongly with radial dyssynchrony. LV torsion (cutoff 0.1 degrees /cm) and twist (cutoff 1 degrees ) at AVC had the highest sensitivity (90%) and specificity (77%) to predict CRT responders among all other parameters, including radial and longitudinal dyssynchrony. In conclusion, LV dyssynchrony is associated with discoordinate rotation of the apical and basal regions, which in turn significantly decreases peak LV twist and torsion and LV twist and torsion at AVC. CRT significantly restored the altered rotational mechanics in responders. These parameters have potential for predicting responders to CRT.     

二尖瓣成形术治疗二尖瓣后叶脱垂

目的分析总结33例非风湿性二尖瓣后叶脱垂成形手术的效果。方法回顾性分析我院2005年5月至2011年5月行二尖瓣成形术治疗二尖瓣后叶脱垂（除外其他合并畸形、风湿性病变及前叶脱垂）患者33例,男性18例,女性15例,平均年龄46．5岁。术前二尖瓣中重度关闭不全9例、二尖瓣重度关闭不全24例。通过部分瓣叶矩形切除、瓣环环缩及成形环的综合运用修复二尖瓣,同期置入二尖瓣爱德华弹性环28枚。结果全组病例均痊愈出院,无围术期死亡。患者术前心脏彩超检查：左房内径（49．26±17．13）mm,左室内径（60．29±8．32）mm,射血分数（66．1±9．6）％,左室短轴缩短率29．78±6．81。术后1周心脏彩超检查：左房内径（40．23±7．93）mm,左室内径（50．63±4．67）mm,射血分数（53．0±8-3）％,左室短轴缩短率23．50±5．01。术后6个月复查心脏彩超检查：左房内径（36．16±7．46）mm,左室内径（45．61±5．67）mm,射血分数（65．0±7．6）％,左室短轴缩短率29．67±5．91。随诊6-70个月,平均随访18．2个月,二尖瓣功能正常或有微量反流22例,有微少量和少量反流9例,有少中量反流2例。无因二尖瓣关闭不全而再次手术者。结论对于二尖瓣后叶脱垂的病变,术中在经食管超声的帮助下,通过部分瓣叶矩形切除、瓣环环缩及成形环的综合运用,能够修复几乎所有非风湿性所导致的二尖瓣后叶脱垂,避免瓣膜置换。对于非风湿性二尖瓣后叶病变,瓣膜成形技术成熟、可靠,修复效果满意。