【作者】 张轶；

【导师】 周启昌；

【作者基本信息】 中南大学 ， 影像医学与核医学， 2009， 博士

【摘要】 目的应用速度向量成像(Velocity Vector Imaging,VVI)技术分析正常人左室扭转运动的特点,建立从新生儿至老年人不同年龄组的正常参考值,评价年龄对左室扭转运动的影响,并与斑点追踪显像(Speckle Tracking Echocardiography,STE)技术测量左室扭转参数比较,评价VVI技术测量正常人左室扭转参数的价值。应用VVI技术观察心肌疾病患者左室扭转运动的改变,包括扩张型心肌病(DCM)、肥厚型心肌病(HCM)、心肌致密化不全(NVM)和心肌炎(MC),并与正常人的扭转参数、常规超声心动图心功能指标射血分数(Ejection Fraction,EF)及实验室指标氮末端脑钠素前体(NT-proBNP)对比,探讨VVI技术评价心肌病患者左心功能的可行性和准确性。方法使用VVI技术分析335例正常志愿者(年龄从12天至74岁)左室扭转运动,观察年龄、性别对扭转参数的影响;从335例志愿者中随机抽取274例进行STE分析,分析两种方法评价左室扭转运动是否有一致性。使用VVI技术分析49例心肌病变患者左室扭转运动参数,使用常规超声心动图测量EF并抽血检测其血浆NT—proBNP含量,分析三种方法所测结果有无相关性。结果左室扭转随年龄增加而变化:扭转角度峰值(Ptw)随年龄增加而增大;使用左室长度标化扭转角度峰值后,3岁以前和25～35岁及35～45岁年龄组的标化后扭转峰值(PtwN)最大;扭转速度峰值(PtwV)从出生至25岁以前随年龄增加,25～45岁保持在相近水平,45岁以后随年龄增加而减小。收缩期扭转的达峰时间(TPKtw)与达峰时间百分比(TPK%)的变化无明显组间差异。最大解旋速度(PutwV)在出生后至3岁前最低,3岁至25岁随年龄增加逐渐增加,25至45岁保持在相近水平,45岁以后随年龄增加而减小。解旋达峰时间(TPKutw)有随年龄增大而增加的趋势,但统计学分析差异无显著性(P＞0.05)。等容舒张期解旋百分比(Iutw%)在3岁前最低,3岁至45岁随年龄增加逐渐增大,45岁以后随年龄增加而减小。不同性别受试者左室扭转运动参数无明显差异。VVI技术所测的左室扭转运动参数与STE技术所测值之间有较好的相关性。DCM组、NVM组、MC组的扭转及解旋各参数均小于正常对照组;HCM组收缩期扭转参数大于对照组,但舒张期解旋各参数明显小于正常对照组。DCM组、NVM组、MC组的收缩期扭转及舒张期解旋参数下降的程度均与EF下降的程度呈正相关,HCM组的解旋参数下降程度与EF下降的程度呈正相关。心肌病组的扭转参数Ptw和TPK%、解旋参数Iutw%的变化与患者血浆NT-proBNP浓度测值有较好的相关性。结论VVI能无创、较准确地评估正常人的左室扭转运动,左室扭转运动随年龄增加的变化反映了新生儿至老年人左室扭转生物力学的成熟和适应性调整过程。VVI技术能无创、准确地评估心肌病变状态下左室扭转运动的变化特点,与超声心动图常用指标和实验室指标有较好的一致性,能为临床评定左室功能提供重要的超声量化指标。更多还原

【Abstract】 Objective Assess the characteristic of Left Ventricular (LV) twist of health person by Velocity Vector Imaging (VVI) , and establish nomogram of LV twist from infancy to the elder. Analyze the influence of aging on LV torsional movement, and compared with the parameter measured by Speckle Tracking Echocardiography (STE) , in order to estimate the value of VVI in assessing of LV twist.Analyze the alteration of LV twist in patients with Cardiomyopathy by VVI, including Dilated Cardiomyopathy (DCM) , Hypertrophic Cardiomyopathy(HCM), Noncompaction of the Ventricular Myocardium (NVM), and Myocarditis (MC) , and compared with the normal twist parameter, routine Echocardiogram heart function index- Ejection Fraction (EF), laboratory index NT-proBNP, to discuss the value of VVI in assessing LV function of patient with Cardiomyopathy.Methods Analyze LV twist in 335 healthy volunteers (aged 12 days to 74 years) by VVI, observe the influence of age and sex on twist parameter. Draw 274 from the 335 healthy volunteers randomly, and assessed by STE, to analysis the consistency in this two methods in evaluate LV twist.Assess LV twist in 49 patients with Cardiomyopathy by VVI, measure the EF by Echocardiogram, detect the content of NT-proBNP in their blood plasma, to discuss the value of VVI in assessment LV function of Cardiomyopathy patient. Analyze the dependability in this three methods, and to evaluate the degree of LV dysfunction in s patients with cardiomyopathy.Results Different LV twist values are noted with respect to age: Peak twist (Ptw) increases gradually with advancing age, when normalized by LV length, it showed higher values before 3 years old and between 25 to 45 years old. Peak twist velocity (PtwV) increased with aging from infancy to 25 years old, and leveled off from 25 to 45 years old, then decreased with advancing age. The changes of time to peak twist velocity (TPKtw ) and % timing of peak twist in systolic duration (TPK%) are indifferent within groups. Peak untwist velocity (PutwV) showed lowest values before 3 years old, and increased with aging from 3 to 25 years old, then leveled off from 25 to 45years old, and decreased with advancing age after 45 years old. Time to peak untwist velocity (TPKutw) increased with aging, but no statistical significance are observed. The proportion of untwist in isovolumetric relaxation period (Iutw%) was lowest before 3 years old, and increased gradually from 25 to 45 years old , then decreased with aging. There are no obvious differences between different sex groups. The parameters of LV twist measured by VVI and STE have good consistency.All of the parameters of LV twist and untwist of DCM, NVM, MC groups are lower compared with control group. The systolic twist parameters of HCM group are higher, but the diastolic untwist parameters are lower than that of control group.The descendent degree of twist and untwist data in DCM, NVM, MC groups are positive correlated with the descendent degree of EF. The deadline of untwist data in HCM group are positively correlated with the deadline of EF. The changes of twist index Ptw, TPK%, and untwist index Iutw% in Cardiomyopathy group are positively correlated with the changes of the NT-proBNP concentration in their blood plasma.Conclusions VVI can be used to noninvasively and accurately assess LV twist of health person. The effect of aging on LV twist may reflect the process of maturational and adaptive modulation of LV torsional biomechanics from infancy to the elder.VVI can be used to noninvasively and accurately assess the changes of LV twist of patients with Cardiomyopathy, and the parameters are positive correlated with the routine Echocardiogram heart function index and laboratory index, provided clinic with the important LV functional data.更多还原