超声心动图对干下型室间隔缺损合并主动脉瓣下隔膜及主动脉瓣关闭不全的诊断价值

目的 总结先天性干下型室间隔缺损合并主动脉瓣下隔膜及主动脉瓣关闭不全的超声心动图特征,并探讨超声心动图对本病的诊断价值.方法 入选15例干下型室间隔缺损合并主动脉瓣下隔膜及主动脉瓣关闭不全患者,超声心动图检测室间隔缺损与主动脉瓣下隔膜的关系,室水平分流特点,主动脉瓣下隔膜引起狭窄的程度,主动脉瓣关闭不全的程度,分析它们之间的相互关系及血流动力学特点.结果 (1)室水平分流频谱为收缩及舒张期连续性左向右分流.(2)主动脉瓣关闭不全的程度与室间隔缺损的大小呈正相关性(0.001＜P＜0.002 5).(3)术前超声测量室间隔缺损数据组比术中实际值小,P＜0.05差异有统计学意义.结论 超声心动图对先天性干下型室间隔缺损合并主动脉瓣下隔膜及主动脉瓣关闭不全的患者,具有较高且独特的诊断价值.     

久居高原对健康青年男性左心室功能和质量影响的研究

目的 研究长期移居高原对健康青年男性左心室功能和质量的影响.方法 对平原青年男性官兵51例,长期移居3 700 m高原的青年男性官兵53例(A组),长期移居3 700 m高原再进4 400m高原50 d的青年男性官兵42例(B组)分别进行血压、心率、指脉氧饱和度及彩色多普勒心脏超声的检测.结果 移居高原两组左室收缩末内径、左心室质量指数显著低于平原对照组(P＜0.05),移居高原A组左室收缩末容积显著低于平原对照组(P＜0.01),移居高原B组室间隔厚度、左心室质量显著低于平原对照组(P＜0.05);移居高原两组左室射血分数、短轴缩短率、每搏输出量、心输出量均显著高于平原对照组(P＜0.05),移居高原B组心脏指数显著高于平原对照组(P＜0.01);移居高原两组心率显著高于平原对照组(P＜0.01),血氧饱和度则显著低于平原对照组(P＜0.01),移居高原B组血氧饱和度显著低于移居高原A组(P＜0.01).结论 久居高原后左心室收缩功能显著高于平原对照组,舒张功能显著低于平原对照组,而久居高原后短期无更高海拔暴露的健康青年男性左室质量与平原对照组无显著差异.     

实时三维超声心动图评价右室不同部位起搏对左室收缩功能及同步性的远期影响

目的 探讨右室不同部位起搏对左室收缩功能及同步性的远期影响.方法 回顾性分析49例植入DDD起搏器术后2年的患者及20例正常人的RT-3DE图像,得到左心室舒张末期容积(LEDV)、左心室收缩末期容积(LESV)、每搏量(SV)、左室射血分数(LVEF)、左室16节段达最小收缩容积所用时间的最大差值(Tmsv16-Dif)及平均时间标准偏差(Tmsv16-SD).结果 A方案:病例组间各参数比较差异无统计学意义.B方案:近心尖组LEDV (P＜0.05)及SV、LVEF (P＜0.01)均小于高位间隔组,Tmsv16-Dif、Tmsv16-SD均大于高位间隔组(P＜0.01).结论 右室高位间隔部起搏的优势显著,是较好的右室起搏部位.     

超声实时三维斑点追踪技术在冠心病诊断中的应用价值

目的 应用超声实时三维斑点追踪技术(3DST)评估冠心病患者早期缺血心肌功能,评价其在冠心病诊断中的应用价值.方法 拟行冠状动脉造影(CAG)且常规超声心动图检查未见室壁运动异常的疑似冠心病患者50例.按CAG结果分为正常对照组20例(CAG未见明显冠脉狭窄),冠心病组30例[冠脉左前降支(LAD)、右冠状动脉(RCA)、左旋支(LCX)中至少有一支主干狭窄≥50％].评估3DST与心肌灌注显像(MPI)诊断冠心病的灵敏度及特异度.结果 冠心病组3DST分析左室整体纵向应变(GLS)和面积应变(AGS)绝对值较对照组明显减低(P＜0.05),差异有统计学意义;以GLS的灵敏度最高;3DST与MPI诊断冠心病的灵敏度差异无统计学意义(P＞0.05).结论 3DST可以定量评估左室壁整体三维应变,可对冠心病早期心肌缺血所致室壁功能异常进行评估,GLS灵敏度较高.     

Analyses of Longitudinal and of Transverse Right Ventricular Function Provide Different Clinical Information in Patients with Pulmonary Hypertension

We tested the hypothesis that analysis of longitudinal right ventricular (RV) function and analysis of transverse RV function by echocardiography provide different clinical information in patients with pulmonary hypertension (PH). Indices of longitudinal and transverse RV function were obtained with different echocardiographic techniques in 30 patients with idiopathic pulmonary arterial hypertension, 28 patients with systolic left ventricular dysfunction and PH (sLVD PH), 27 patients with sLVD and normal pulmonary pressure (sLVD no PH) undergoing right heart catheterization and 20 healthy patients. Indices of RV transverse function were significantly worse in patients with PH than in patients without PH and did not statistically differ between patients with normal and those with reduced cardiac index; RV diameter shortening at mid-segment correlated best with mean pulmonary artery pressure (h = 0.63, p < 0.001). Indices of longitudinal function were poorly related to severity of PH, but a tricuspid annular plane systolic excursion <15 mm predicted a cardiac index <2.5 L/min/m² with 80% sensitivity and 93% specificity (area under curve = 0.85). In conclusion, in patients with PH, reduced transverse RV function is a reliable indicator of the presence of high pulmonary artery pressure, whereas reduced RV longitudinal function is associated with impairment of cardiac function.     

Viscoelastic Properties of Normal and Infarcted Myocardium Measured by a Multifrequency Shear Wave Method: Comparison with Pressure-Segment Length Method

Our aims were (i) to compare in vivo measurements of myocardial elasticity by shear wave dispersion ultrasound vibrometry (SDUV) with those by the conventional pressure-segment length method, and (ii) to quantify changes in myocardial viscoelasticity during systole and diastole after reperfused acute myocardial infarction. The shear elastic modulus (μ₁) and viscous coefficient (μ₂) of left ventricular myocardium were measured by SDUV in 10 pigs. Young's elastic modulus was independently measured by the pressure-segment length method. Measurements made with the SDUV and pressure-segment length methods were strongly correlated. At reperfusion, μ₁ and μ₂ in end-diastole were increased. Less consistent changes were found during systole. In all animals, μ₁ increased linearly with left ventricular pressure developed during systole. Preliminary results suggest that μ₁ is preload dependent. This is the first study to validate in vivo measurements of myocardial elasticity by a shear wave method. In this animal model, the alterations in myocardial viscoelasticity after a myocardial infarction were most consistently detected during diastole.