电影磁共振成像评价急性心肌梗塞后左室重构的实验研究

目的探讨电影磁共振成像在评价急性心肌梗塞后左室重构方面的价值。方法对２５只犬分别于冠状动脉左前降支结扎术前和术后３小时进行电影磁共振成像检查,并测量舒张末期和收缩末期梗塞和非梗塞心肌节段的室壁厚度、长度及左室容积。结果电影磁共振成像能动态观察各心肌节段的室壁运动情况,能清晰准确地显示梗塞区室壁伸展、左室扩大和左室收缩功能受损情况。结论电影磁共振成像能为临床及早发现左室重构提供更加准确可靠的依据     

磁共振延迟增强扫描对心肌梗死的诊断价值与ECG和UCG的对比分析

目的：探讨磁共振延迟增强扫描对心肌梗死的诊断价值。方法：14例心肌梗死患者均行磁共振延迟增强扫描,分析结果并与心电图（ECG）及超声心动图（UCG）对比。结果：14例心梗患者共分析238个节段,其中低灌注及灌注缺损节段共102（42.9%）个,磁共振延迟增强结果显示128（53.9%）个节段对比剂滞留呈高信号坏死改变,61个延迟高信号节段对应室壁ECG导联无病理性Q波出现,5例UCG未见节段性室壁运动异常。结论：心脏磁共振多序列扫描可在一次检查中完成,它无创、空间分辨率高,可获取心脏形态、功能信息,延迟增强扫描可识别心内膜下心肌梗死,区分透壁程度,鉴别活性心肌,间接判断冠脉血管病变情况,对心肌梗死的诊断、预后判断和治疗方案的制定具有非常重要的作用。     

三维超声心动图定量左室局部射血分数对诊断室壁瘤的价值:与左室X-线造影的对照研究

目的探讨三维超声心动图定量分析左室节段收缩功能对心肌梗死后室壁瘤形成的诊断价值。方法38例心肌梗死患者分别进行了常规心电图检查、二维超声心动图检查、三维超声心动图检查及多投照体位左室造影检查，三维超声心动图定量分析左室节段收缩功能以左室节段射血分数为负值定义为局部室壁瘤形成，以左室造影为标准，计算3种方法诊断室壁瘤的敏感性和特异性。结果以左室造影为标准，常规心电图检查、二维超声心动图检查、三维超声心动图定量左室节段收缩功能分析诊断室壁瘤的特异性和敏感性分别为75％和92．3％，81．2％和92．8％，100％和94．1％。结论采用实时（动态）三维超声心动图定量分析左室节段射血分数能更准确地诊断心肌梗死后室壁瘤，其敏感性和特异性均显著高于二维超声心动图。     

心脏磁共振和超声诊断肥厚性心肌病的价值

目的分析心脏磁共振(CMR)成像技术和超声心动图对肥厚性心肌病(HCM)的诊断,探讨两种方法诊断HCM的价值。方法 53例HCM患者均进行3.0 T CMR和超声心动图检查。CMR检查包括常规成像、灌注及延迟强化,测量心肌厚度,评价心肌延迟强化特点。超声心动图测量左室壁各节段心肌厚度,评价左室流出道梗阻程度。比较CMR和超声心动图评价心肌厚度及纤维化能力的差异。结果肥厚性心肌病CMR和超声心动图测量心肌各节段厚度除侧壁外,两种方法测量其余室壁心肌厚度值的差异无统计学意义。CMR表现为延迟强化39例,7例局限性强化,5例弥漫性强化,2例透壁性强化,异常强化灶分布在游离壁和室间隔交界区、室间隔。超声心动图显示44例患者有左室流出道梗阻。结论心脏超声在测量心脏除侧壁外其余节段厚度时不劣于CMR,而测量侧壁时存在一定误差,易高估侧壁厚度。CMR可用于心肌纤维化的定量检测。超声心动图可以实时显示二尖瓣收缩期前向运动,评价左室流出道梗阻程度优于CMR。     

实时三维超声心动图评价左心室整体和节段容积及收缩功能的临床研究

目的研究实时三维超声心动图(RT-3DE)对左心室整体和节段容积以及收缩功能的临床价值。方法选择2013年3月至2014年3月保定市第二中心医院收治的急性前壁心肌梗死患者40例、陈旧性前壁心肌梗死患者50例、同期健康志愿者44例为研究对象,所选患者均进行RT-3DE检查,通过相关的分析软件得到节段及整体容积-时间曲线,节段和整体收缩末期容积。结果急性前壁心梗组及陈旧性前壁心梗组患者左室舒张末内径明显高于对照组,十六节段射血分数低于对照组,两组比较差异有统计学意义(P0.05)。两组前壁心肌梗死患者左室整体节段收缩末期容积均大于对照组,梗死节段以及邻近梗死区域的大多数整体收缩末期容积均大于对照组。结论急性以及陈旧性心肌梗死患者的左室整体及节段舒缩功能能够运用RT-3DE准确评价,左室整体及节段收缩功能降低会对室壁运动的同步性产生影响。     

速度向量成像技术评价心肌梗死节段室壁径向收缩能力的价值

目的 探讨速度向量成像(VVI)技术评价心肌梗死节段径向收缩能力的价值.方法 将雄性Wister大鼠分为两组,一组结扎冠状动脉制成心肌梗死模型组(10只),另一组同样进行手术但不结扎冠状动脉作为对照组(14只).应用VVI技术对左室短轴乳头肌水平室壁径向应变及应变率进行分析.结果 心肌梗死组梗死节段(左室前壁及前间隔)径向应变及应变率较对照组相应节段明显减低,两组间差异具有统计学意义(P<0.05).对照组各节段室壁应变及应变率比较差异无统计学意义(P>0.05).结论 VVI技术能够定量评价心肌梗死节段室壁的径向收缩能力.     

心脏磁共振延迟强化成像定量评价心肌梗死的研究

目的 研究计算机辅助测体积法(CAVM)与视觉评分法(VSM)在心脏磁共振延迟强化成像上评价梗死心肌大小的相关性,并探讨梗死心肌质量与室壁运动异常、左室功能的相关性.方法 采用多次屏气平衡稳态自由进动快速成像(FIESTA)序列,对21例心肌梗死患者行心脏电影MRI及钆喷替酸葡甲胺(Gd-DTPA)增强的延迟强化成像.①用CAVM及VSM分别评价患者的梗死心肌质量及梗死心肌范围程度.用VSM评价时根据延迟强化的透壁程度分为0～4分;0＝无强化,1＝1%～25%强化,2＝26%～50%强化,3=51%～75%,4=76%～100%强化;②评价患者的室壁运动异常及左室功能.结果 两种方法评价梗死心肌高度相关(r=0.825,P＜0.001);梗死心肌质量与室壁运动异常(r=0.740)、射血分数(r=-0.733)、收缩末期容积指数(r=0.702)、收缩末期容积(r=0.698)、舒张末期容积指数(r=0.657)、舒张末期容积(r=0.648)均密切相关(P≤0.001).结论 计算机辅助测体积法及视觉评分法均可准确定量梗死心肌,梗死心肌质量与室壁运动异常、左室功能有高度相关性.     

左心壁淋巴管瘤误诊为假性室壁瘤一例

患者,男性,４２岁,因间断心悸３年,加重１个月入院。心电图示陈旧性下壁、正后壁、高侧壁心肌梗死,Ｘ线诊断为室壁瘤;动态核素心室造影疑假性室壁瘤,核磁共振及超高速ＣＴ均示假性室壁瘤。心血管造影：未见造影剂流向左室腔外;冠状动脉未见狭窄梗阻性病变,可见前降支造影剂流向左室腔,诊断为前降支－左心室漏。超声心动图：房室大小及室壁厚度正常,左室下壁基底段运动幅度及收缩增厚率减低,后侧壁可见一大无回声腔（约３０ｃｍ×５０ｃｍ）向心外膨出,瘤体无收缩活动,似借一窄交通口与左室相通（图１）,各瓣膜未见异常。彩超…     

血流向量成像评价室壁瘤患者左心室收缩期血流动力学特点

目的 探讨血流向量成像(vector flow mapping,VFM)技术检测心肌梗死并发室壁瘤患者室壁节段性运动异常的心腔内血流流场的变化规律。方法 心肌梗死并发室壁瘤患者31例和健康志愿者35例,应用VFM技术分析其等容收缩期、快速射血期及缓慢射血期的涡流及流线特征、收缩早期左室流出道速度阶差(△V)和室壁瘤瘤颈部平均血流量的变化。结果 室壁瘤组与对照组的不同主要体现在室壁瘤体内收缩期持续存在涡流;室壁瘤组瘤体内涡流横径与纵径乘积与二维超声测量室壁瘤横径与纵径乘积显著相关(P＜0.01);室壁瘤组收缩期涡流持续时间占整个收缩期百分比（并用心率标化）显著高于对照组(P＜0.01);室壁瘤患者收缩早期左室流出道速度阶差(△V)明显降低(P＜0.05);经过室壁瘤瘤颈的平均血流量明显减少(P＜0.01)。结论VFM技术能够直观显示室壁瘤患者左室心腔内血流动力学变化,定量测量局部血流速度及血流量。     

应用药物负荷心脏MRI探讨冠心病心肌收缩功能与心肌灌注的关系

目的本研究主要探讨心脏MRI(CMRI)结合药物(小剂量ATP)负荷试验中,心肌收缩功能与心肌灌注之间、心肌收缩功能储备与心肌灌注储备之间的关系。方法我们采用1.5T磁共振扫描仪对68例冠心病患者进行了心脏电影MR成像,其中19例患者冠状动脉造影证实有阳性结果(血管狭窄>50%)。真正快速稳态梯度回波(FIESTA)序列用于观察静息状态下和小剂量ATP负荷状态下的心肌运动;平面回波成像(EPI)序列用于ATP负荷前后的MR心肌灌注成像。各序列均采用左室短轴位成像。电影MRI图像采用MASS软件包对左室各节段室壁运动进行半定量计分,同时对灌注曲线进行定量分析。最后对各节段心肌灌注参数和室壁运动评分进行统计分析。结果在静息状态和负荷状态下,心肌灌注参数均随着室壁运动评分的增加而降低。在小剂量ATP负荷状态下室壁运动较负荷前改善的心肌节段较无改善者的心肌灌注储备值低。结论心肌灌注和心肌收缩功能具有很好的相关性,对两者的综合判断有助于提高CMRI评估心肌活性的价值。     

Isolated noncompaction of the ventricular myocardium: ultrafast computed tomography and magnetic resonance imaging

This study was undertaken to evaluate the feasibility of ultrafast computed tomography (CT) and magnetic resonance imaging (MRI) for anatomical and pathophysiological diagnosis of isolated noncompaction of the left ventricular myocardium (INVM) compared with other imaging modalities including thallium myocardial imaging. Six patients, three sets of siblings, ranging in age from 13 to 18 years, were included in this study. Two-dimensional echocardiograms revealed numerous prominent trabeculations and deep intertrabecular recesses in one or more ventricular wall segments in all cases. Thallium-201 myocardial imaging disclosed a hypoperfusion area corresponding to the zones where noncompacted ventricular myocardium was localized. Ultrafast CT showed early defects of varying degrees and rate enhancement of the noncompacted ventricular myocardium, implying fibrosis in this area. MRI disclosed inner zones of noncompacted myocardium distinguishable from thin outer zones of compacted myocardium. T2-weighted imaging revealed high intensity areas at the apex of the left ventricle, suggesting disturbed microcirculation due to fibrosis, thrombus formation, and hypokinesis. Cine MRI revealed hypokinesis of the noncompacted ventricular wall during the cardiac cycle. In conclusion, ultrafast CT and MRI provide high-resolution imaging of noncompacted myocardium, and also pathophysiological details regarding this rare disease.     

多普勒组织成像检测冠心病室壁运动及心肌活性的应用价值

本文报道了应用多普勒组织成像（ＤＴＩ）检测冠心病室壁运动异常，并配合小剂量多巴酚丁胺负荷超声心动图判断心肌活性。结果显示：冠心病室壁运动异常节段的收缩期，舒张期速度均低于正常组（Ｐ＜０．０５）。应用小剂量多巴酚丁胺后，１００个异常节段中，３５个节段运动改善（心肌存活组，Ａ组），６５个节段无明显变化（坏死心肌组，Ｂ组）；ＤＴＩ检测Ａ组的收缩期速度Ｖｓ与速度增长率ＶＲ均明显高于Ｂ组。表明ＤＴＩ对心肌缺血及缺血心肌活性的判断有一定价值     

A giant inferoposterior true aneurysm of the left ventricle mimicking a pseudoaneurysm

A left ventricular aneurysm (LVA) is most commonly the result of myocardial infarction, usually involving the anterior wall. A left ventricular pseudoaneurysm (LVPSA) or false aneurysm forms when cardiac rupture is contained by adherent pericardium or scar tissue. The accurate diagnosis, although difficult to establish, is an important one to make because these aneurysms are prone to rupture. In this article, we report a challenging case of a cardiac aneurysm a year after a coronary bypass operation which could not be definitively diagnosed despite of imaging with different techniques including echocardiography, coronary angiography, left ventriculography and magnetic resonance imaging (MRI). The patient underwent a second cardiac surgery, the aneurysm was resected, the mitral valve was replaced and the defect in the ventricular wall was repaired. Because of the combined diagnostic capabilities like detailed and functional pathoanatomy and aneurysmal wall characterization, MRI seems to have multiple advantages in differential diagnosis.     

Enoximone very low-dose dobutamine stress echocardiography: a new test for detecting viability in severe myocardial dysfunction after acute myocardial infarction.

Relying on the synergistic action on contractility of enoximone and dobutamine when concomitantly infused, 25 patients with their first acute Q-wave anterior myocardial infarctions underwent conventional low-dose dobutamine echocardiography (LDE) and enoximone very-LDE to assess myocardial viability in severely dysfunctioning areas. Images were recorded at peak of pharmacodynamic effect of drugs and 4 months after revascularization. At peak-dose stage of LDE and enoximone very-LDE the regional infarct zone wall-motion score significantly decreased from the basal value of 25.6 +/- 2.9 to 16 +/- 6.0 (P <.001) and to 14.5 +/- 5.2 (P <.001), respectively. A high correlation was found by comparing the wall-motion score of each patient calculated at peak effect of combined drug administration with follow-up values (r(s) = 0.9). Enoximone very-LDE has proven to be a new test useful to evaluate viability in asynergic segments especially when the results of conventional tests are questionable.     

Milrinone echocardiographic viability test: a pilot study.

We assessed the utility of milrinone to predict recovery of function after surgical myocardial revascularization in patients with severe baseline left ventricular systolic dysfunction caused by coronary artery disease (CAD). Prediction of viable myocardial segments that will regain function after revascularization may help in the selection of patients who will benefit from coronary artery bypass graft surgery (CABG) as well as aid in the choice of target sites for coronary revascularization. We investigated 20 consecutive patients with CAD and left ventricular ejection fraction < or = 40% who had evidence of myocardial viability by either thallium scan or dobutamine viability test and were candidates for elective CABG. Left ventricular regional wall motion and global ejection fraction were assessed by transesophageal echocardiography in the operating room. Measurements were done before and 10 minutes after milrinone infusion, and immediately after CABG. Left ventricular wall motion score was derived by means of a 12-segment model. Functional improvement for each segment was defined as a wall motion change > 1. Baseline ejection fraction was 27% +/- 5% (mean +/- SD). Ejection fraction increased to 35% +/- 5% after milrinone infusion (P < .0001) and to 36% +/- 6% after CABG (P < .0001). Post-CABG ejection fraction was significantly correlated with postmilrinone ejection fraction (r = 0.65, P < .0001). Milrinone infusion resulted in augmentation of contraction in 98 of the 209 abnormal segments (wall motion score > or = 2); 91 (92.9%) of these improved after CABG. One hundred nine of the 111 segments that showed no improvement with milrinone did not improve after revascularization (98.2%). Seventy-three segments were akinetic or dyskinetic at baseline; 46 (63.0%) of these improved with milrinone. Improvement in regional wall motion after revascularization was detected in 84.8% of the segments that improved with milrinone versus only 3.7% of the segments that did not improve with milrinone. In patients with ischemic cardiomyopathy, improvement in left ventricular function (segmental wall motion and global ejection fraction) during milrinone infusion is highly predictive of improvement after CABG.     

Prediction of long-term reverse left ventricular remodeling after revascularization or medical treatment in patients with ischemic cardiomyopathy: a comparative study between SPECT and MRI

Patients with ischemic heart disease and depressed left ventricular (LV) ejection fraction (LVEF) develop varying degrees of LV remodeling after cardiac surgical revascularization. Fifty-three patients with stable ischemic heart disease and impaired LV function (LVEF 34.9 ± 4%) were prospectively followed up for 24 months. Thirty-seven patients underwent coronary artery bypass grafting (CABG), 16 patients were treated conservatively. Cardiac magnetic resonance imaging (MRI) and SPECT were performed at baseline and after 12 and 24 months of follow-up. The patients were divided into responders and non-responders depending on the degree of LVEF improvement at 24 months follow-up (>5%—responders). MRI with ≤5 segments with DE/wall thickness ratio (DEWTR) ≥50% predicted LV reverse remodeling with a sensitivity of 86% and a specificity of 75% (AUC 0.81). An MRI finding of ≤2 segments with the DEWTR ≥75% had a corresponding sensitivity of 71% and specificity of 67% (AUC 0.75) while fixed perfusion defect on SPECT < 16.5% of LV predicted reverse remodeling with a sensitivity of 64% and a specificity of 69% (AUC 0.64). A preoperative number of segments with the DE/wall thickness ratio of ≥50 and ≥75% obtained by MRI, was found to be a better predictor of left ventricular reverse remodeling than fixed perfusion defect by SPECT. No other MRI or SPECT parameter predicted LVEF improvement at 24 months after CABG.     

The role of interventricular septum in kinetics of left and right ventricular contraction in patients with ischemic heart disease and chronic cardiac failure

AIM: To study the role of interventricular septum (IVS) in kinetics of left ventricular (LV) and right ventricular (RV) contraction in IHD patients with chronic cardiac failure (CCF). MATERIAL AND METHODS: Standard equilibrium biventricular radioventriculography was used for the study of an inotropic function of LVand RV myocardium in 117 IHD patients with CCF of NYHA FC I-IV (mean age 58+/-4.1 years). Local myocardial contractility was studied with a unified 16-segment L V and RV model. RESULTS: Segments, local ejection fraction (EF) of which exceeded 50% were considered as normokinetic, 25-50%--hypokinetic, under 25%--akinetic. Total EF of both ventricles in all patients with FCI-II CCF was normal being 63.6+/-4.6% in the left and 53.4+/-5.2% in the right ventricle. Alterations of segmental contractility as zones of hypo- and akinesia of primarily anteroseptal region of the ventricles were revealed. Patients with CCF of FC III had zones of interventricular septum (IVS) akinesia and hypokinesia of its free wall in lowering of LV EF to 43.2+/-6.3%. RV EF also decreased to 38.4+/-4.8%, IVS diskinesia zones appeared due to pulmonary hypertension. Patients with CCF of FC IV had LV EF of 15.1+/-4.1%, RV EF was 25.9 +/-6.8% with more definite disorders of segmentary contractility in the form of increased percentage of dys- and akinetic segments in the septal region and a free wall of both ventricles. CONCLUSION: In IHD patients with initial CCF defects in local contractility occurred in IVS segments. With progression of CCF, lowering of total EF of both ventricles was associated with deterioration of local dysfunction in the form of increased proportion of hypo-, dys- and akinesia zones.     

多普勒组织成像对冠心病局部室壁运动异常的研究

目的 探讨多普勒组织成像（ＤＴＩ）检测冠心病局部室壁运动异常的临床应用价值。方法 应用ＤＴＩ技术对５４例临床确诊（其中３０例经冠脉造影证实）的冠心病患者和３０例正常对照者左室壁节段长轴及短轴方向运动速度进行检测,并与常规二维超声心动图（２ＤＥ）检查结果对照分析。结果 冠心病患者２ＤＥ显示运动异常的空壁节段,二维彩色及Ｍ型ＤＴＩ表现为色彩变暗、消失或呈相反方向的色彩。脉动波多普勒组织成像（ＰＷ－ＤＴ     

Local myocardial contractility in patients with coronary heart disease and chronic heart failure

The aim of the study was to evaluate the peculiarities of local left and right ventricular myocardial contractility in patients with coronary heart disease (CHD) and various degrees of chronic heart failure (CHF) using biventricular radioventriculography (RVG). Local left and right ventricular myocardial contractility was evaluated in 127 patients with CHD and CHF using RVG with a standard procedure of segmentary and phase histogram analysis. The patients were divided into two groups according to left ventricular ejection fraction (LVEF). Group I consisted of 89 CHD patients with NYHA II-III CHF and LVEF of > 40%; group II included 38 CHD patients with NYHA III-IV CHF and LVEF of < 40%. The significant decrease of LVEF in group II was caused by the prevalence of hypo- and akinetic segments in the structure of local contractility. In both groups total LVEF was maintained by lateral wall segments. Right ventricular contractility in patients with CHD and CHF was maintained by anteroseptal segments.