Right ventricular strain and strain rate properties in patients with right ventricular myocardial infarction

BACKGROUND: This study was planned to assess strain and strain rate properties of right ventricle in patients with RV myocardial infarction. MATERIAL AND METHOD: Thirty patients with acute inferior myocardial infarction were included in this study. The presence of right ventricular infarction in association with an inferior myocardial infarction was defined by an ST-segment elevation 0.1 mV in lead V4 R. According to this definition, 15 patients had electrocardiographic signs of inferior myocardial infarction without right ventricular infarction (group I), and 15 patients had electrocardiographic signs of inferior myocardial infarction with right ventricular infarction (group II). Echocardiography was performed using a Vivid 5 System (GE Ultrasound; Horten, Norway) and a 2.5-MHz transducer. 2-dimensional color doppler myocardial imaging (CDMI) data for longitudinal function were recorded from the RV free wall using standard apical view. Offline analysis of the myocardial color Doppler data for regional velocity (V), strain rate (Sr), and strain (S) curves was performed using a special software program (EchoPac 6.4 Vingmed, Horten, Norway). They were assessed in basal, middle and apical segments of the RV. The differences between different groups were assessed with the Mann-Whitney U-test. A value of P < 0.05 was considered statistically significant. RESULTS: Systolic tissue velocity, strain, strain rate of basal (4.8 +/- 0.8 cm/s vs 6.5 +/- 1.2 cm/s, -12 +/- 3% vs -24 +/- 5%, 1.28 +/- 0.3/s vs -1.9 +/- 0.4/s; P < 0.001, <0.001, <0.001, respectively) and mid (4.2 +/- 0.5 cm/s vs 5.4 +/- 0.5 cm/s, -16 +/-3% vs -26 +/- 4%, -1.2 +/- 0.3/s vs -2.1 +/- 0.3/s; P < 0.001, <0.001, <0.001, respectively) segments of right ventricle were significantly lower in patients with RV infarction than in patients without RV infarction. There were no differences between groups for apical strain, strain rate, and systolic tissue velocity. CONCLUSION: This study demonstrates that right ventricular strain and strain rate were lower in patients with left ventricular inferior wall myocardial infarction with, compared to without, right ventricular infarction.     

Left and right atrial myocardial deformation properties in patients with an atrial septal defect

Background: Atrial septal defect (ASD) is a common form of congenital heart defect in adults, which affects all cardiac chambers. Atrial myocardial function in patients with ASD has not yet been clearly elucidated. The aim of this study was to investigate atrial myocardial deformation properties in patients with ASDs. Methods: The study involved 24 patients with a secundum type ASD, and 22 healthy subjects. Color Doppler myocardial imaging was used to measure left and right atrial myocardial systolic strain and strain rate values, together with peak systolic velocity, early velocity, and late diastolic velocity. Results: There was no significant difference between the two groups with regard to age, gender, body mass index, heart rate, blood pressure, left atrial diameter, and ventricular function. The peak systolic atrial myocardial strain and strain rate values in each of the atrial walls studied were lower in the ASD group compared to those of the control group, but the difference reached statistical significance only in the case of the right atrial wall (right atrial strain: 48.0 ± 32.7% vs 100.2 ± 46.6%, P = 0.006; right atrial strain rate: 2.6 ± 1.2/sec vs 3.8 ± 1.2/sec, P = 0.024). Conclusion: The left to right cardiac shunt that results from ASD leads to a reduction in the right atrial myocardial longitudinal lengthening that occurs during ventricular ejection. These findings demonstrate that the reservoir function of the atrium is impaired and atrial stiffness increases in patients with ASDs.     

Correlation of false negative myocardial infarct scintigraphy with postmortem studies

Negative myocardial infarct scintigrams with 99mtechnetium stannous pyrophosphate (99mTc-PYP) were obtained in two patients with acute massive transmural infarct. Both patients died soon after scintigraphy. Because necropsy was performed within hours after death, we were able to correlate the distribution of the tracer within the acutely infarcted tissue with the myocardial scintigram. The clinical implication is that a single myocardial scintigram may be grossly inaccurate in detecting and quantifying infarct size. The scintigraphic findings should always be correlated with the electrocardiographic and enzymatic findings in evaluating patients with possible myocardial infarct.     

Sustained postinfarction myocardial oedema in humans visualised by magnetic resonance imaging

OBJECTIVE—To demonstrate postinfarction myocardial oedema in humans with particular reference to the longitudinal course, using magnetic resonance imaging (MRI).
DESIGN—Prospective observational study. Subjects were studied one week, one month, three months, six months, and one year after presenting with a myocardial infarct.
SETTING—Cardiology and magnetic resonance departments in a Danish university hospital.
PATIENTS—10 patients (three women, seven men), mean (SEM) age 58.2 (3.20) years, with a first transmural myocardial infarct.
MAIN OUTCOME MEASURES—Location and duration of postinfarction myocardial oedema.
RESULTS—All patients had signs of postinfarction myocardial oedema. The magnetic resonance images were evaluated by two blinded procedures, employing two MRI and two ECG observers: (1) MRI determined oedema location was compared with the ECG determined site of infarction and almost complete agreement was found; (2) the time course of postinfarction myocardial oedema was explored semiquantitatively, using an image ranking procedure. Myocardial oedema was greatest at the initial examination one week after the infarction, with a gradual decline during the following months (Spearman's rank correlation analysis: ρ_{observer 1} = 0.94 (p < 0.0001) and ρ_{observer 2} = 0.97 (p < 0.0001)). The median duration of oedema was six months.
CONCLUSIONS—Postinfarction myocardial oedema seems surprisingly long lasting. This observation is of potential clinical interest because the oedema may have prognostic significance.


Keywords: myocardial infarction; myocardial oedema; magnetic resonance imaging     

Role of left ventricular dyssynchrony in predicting remodeling after ST elevation myocardial infarction

Background: Intraventricular dyssynchrony is associated with worsening systolic function, adverse remodeling, and clinical events. The aim of this study is to investigate whether intraventricular dyssynchrony assessed by tissue Doppler imaging (TDI) can predict left ventricular (LV) remodeling after first ST segment elevation myocardial infarction (STEMI) treated successfully with primary percutaneous coronary intervention (pPCI). Methods: Fifty‐two consecutive patients who presented with first acute STEMI were included in the study. All patients underwent successful pPCI. Standard echocardiography was performed within 48 hours of admission. LV dyssynchrony was assessed by color‐coded TDI. Dyssynchrony (Ts‐diff) was calculated by maximal temporal difference between time to peak systolic velocities (Ts) of six basal segments. Echocardiographic examination was repeated after 6 months to reassess LV volumes. LV remodeling was defined as >15% increase in LV end‐systolic volume index (LVESVI) after 6 months. Results: Eleven patients (23%) developed LV remodeling. Baseline dyssynchrony was found to be correlated with percent change in LVESVI and LV end‐diastolic volume index (LVEDVI) after 6 months. Ts‐diff, creatine kinase‐MB and mitral inflow E‐wave deceleration time (DT) were the independent predictors of remodeling after STEMI in multivariate logistic regression analysis. Receiver operating characteristic curve analysis showed that Ts‐diff >56 msec had 72.7% sensitivity and 83.8% specificity for predicting remodeling. Conclusions: LV dyssynchrony is a strong predictor of LV remodeling after acute myocardial infarction (AMI). It could be useful in risk stratification of patients after AMI. (Echocardiography 2012;29:165‐172)     

硝酸甘油介入~(99m)Tc-甲氧基异丁基异腈心肌灌注断层显像评估存活心肌

目的　评估静息及硝酸甘油介入99mTc 甲氧基异丁基异腈 (99mTc MIBI)心肌灌注断层显像在存活心肌检测中的应用价值。方法　对心肌梗死 2 0例于血管重建术前分别行静态及硝酸甘油介入显像 ,血管重建术后 1个月重复静息心肌显像并进行对比分析。结果　 2 0例共有 1 4 4个异常灌注的心肌节段 ,硝酸甘油介入后有 72个心肌节段灌注改善 ,血管重建术后有 77个心肌节段灌注改善。硝酸甘油介入改善的 72个节段术后有 62个节段改善 ;而术前无改善的 72个节段术后只有 1 5个节段改善 ,硝酸甘油介入99mTc MIBI心肌灌注显像对存活心肌预测的阳性预测值为 86 .1 % ,阴性预测值为 79.2 % ,预测准确率为 82 .6%。结论　硝酸甘油介入99mTc MIBI心肌灌注断层显像是可供临床检测心肌存活的安全、有价值的方法     

老年急性心肌梗死患者的组织谐波超声心动图检查

目的探讨组织谐波超声心动图(THE)在老年人急性心肌梗死诊断中的应用价值。方法对本院136 例经THE检查的老年初发Q波急性心肌梗死患者的临床及超声心动图资料进行分析。结果男95例,女41例,年龄60-89岁,平均(68±7)岁。THE图像满意率92％(125/136)。THE图像满意者中检出急性心肌梗死117例(94％)。 THE与心电图判断心肌梗死的部位及范围基本一致,尤其是对于急性广泛前壁和前壁心肌梗死,两者的判断高度一致。THE所示心肌梗死部位与冠状动脉造影所示梗死相关动脉供血区域符合率93％。结论 THE能够敏感、准确地检出老年急性心肌梗死患者,可作为早期诊断老年人急性心肌梗死的补充手段。     

磁共振心肌灌注成像预估急性心肌梗死疗效的临床研究

目的 :采用磁共振 (MR)首过灌注成像分析急性心肌梗死 (AMI)心肌首过灌注特点 ,评价病变心肌组织血流灌注治疗效果。方法 :AMI患者 16例 ,正常对照组 8例。采用TurboFLASH序列行MR首过灌注及延迟成像扫描 ,绘制左心室各壁心肌信号强度 时间曲线 ,分析病变心肌信号强度 时间曲线特点。结果 :AMI未溶栓者首过不强化 ,延迟扫描信号强度高于正常心肌 ,曲线上升时间、上升斜率、峰值时间和对比增强率明显低于正常心肌 ,峰值信号强度仅为正常心肌的 (5 4 .5± 12 .0 ) %。溶栓再灌注者首过及延迟均强化 ,延迟扫描时病变心肌信号强度高于正常心肌 ,信号强度 时间曲线仅曲线上升时间延长 ,峰值信号强度可达正常心肌的 (90 .8±13.0 ) %。结论 :TurboFLASH序列可反映心肌首过灌注 ,分析心肌首过灌注有助于评价病变心肌血流灌注情况 ,评价溶栓疗效     

多普勒组织成像技术在心肌梗死心功能评价中的应用

目的:研究多普勒组织成像(DTI)技术评价心肌梗死的临床应用价值。方法:回顾性分析应用DTI及彩色多普勒超声心动图(UCG)检查30例急性心肌梗死(AMI)患者的资料。结果:①AMI后2周,3个月,6个月时左室舒张功能显著减退(P<0.01),而左室收缩功能在2周时显著降低(P<0.01),随时间的推移略有改善;②AMI患者DTI速度图显像能更直观反应梗死相关局部的心肌室壁病变;③AMI患者2周时DTI频谱图特征:收缩波,舒张早期波E波和E／A(舒张晚期波)振幅比值降低(P均<0.01)。结论:DTI技术为观察AMI后心肌的室壁运动,心脏的收缩和舒张功能提供了一个直观,而且重复性好的有效方法。     

Early prediction of myocardial viability after acute myocardial infarction by two-dimensional speckle tracking imaging

Background Identifying the transmural extent of myocardial necrosis and the degree of myocardial viability in acute myocardial infarction (AMI) is important clinically. The aim of this study was to assess myocardial viability using two-dimensional speckle tracking imaging (2D-STI) in patients with AMI. Methods 2D-STI was performed at initial presentation, three days, and six months after primary percutaneous coronary intervention (PCI) in 30 patients with AMI, who had a left anterior descending coronary artery (LAD) culprit lesion. In addition, 20 patients who had minimal stenotic lesions (< 30% stenosis) on coronary angiography were also included in the control group. At six months dobutamine echocardiography was performed for viability assessment in seven segments of the LAD territory. According to the recovery of wall motion abnormality, segments were classified as viable or non-viable. Results A total of 131 segments were viable, and 44 were nonviable. Multivariate analysis revealed significant differences between the viable and nonviable segments in the peak systolic strain, the peak systolic strain rate at initial presentation, and peak systolic strain rate three days after primary PCI. Among these, the initial peak systolic strain rate had the highest predictive value for myocardial viability (hazard ratio: 31.22, P < 0.01). Conclusions 2D-STI is feasible for assessing myocardial viability, and the peak systolic strain rate might be the most reliable predictor of myocardial viability in patients with AMI.     

磁共振延迟增强显像诊断心肌梗死的临床研究

目的 了解磁共振延迟增强(MR-DE)显像在心肌梗死诊断中的临床意义。方法 42例拟诊冠心病的患者,按临床分为心肌梗死、心肌缺血、正常3组,行MR-DE显像,其中25例行冠状动脉造影(CAG),并按冠脉狭窄程度分为狭窄<50％,50％～99％和100％3组。计算MR-DE检出心肌梗死的敏感性与特异性,并分别分析临床分组和CAG分组的MR-DE结果。结果 利用延迟增强判断心肌梗死,敏感性、特异性和诊断准确性分别为87.5％,94.1％和92.8％。出现延迟增强的比例,在临床分组中,分别为87.5％,8.7％和0％;在CAG分组中,分別为0％,50％和100％。结论 MR-DE显像对心肌梗死诊断有较高临床意义。     

应变率成像对急性前壁心肌梗死冠脉介入治疗后左室局部收缩功能的评价

目的运用应变率成像（SRI）技术定量评价急性前壁心肌梗死患者经皮冠状动脉介入术（PCI）前后梗死相关血管供血区域局部收缩功能。方法对62例急性前壁心肌梗死患者行PCI术。血管开通后无复流13例（无复流组）,心肌灌注良好49例（灌注组）。分别于PCI术前、术后3d、1个月及6个月测量左前降支参与供血的9个室壁节段的沿长轴收缩期应变率（SR）并与术前比较,确定异常节段。结果两组各时点sR降低,灌注组术后不同时间点的SR均显著高于无复流组,绝大多数心肌节段SR较术前增加,且随着时间的推移,其SR逐渐增加;无复流组术后3d及1个月除极少数节段SR降低外,其他节段心肌SR与术前无明显差异;术后6个月部分心肌节段SR较术前及术后3d有所增加。结论SRI可动态观察急性前壁心肌梗死PCI术前、术后梗死相关血管供血区域心肌收缩功能,间接评估心肌灌注情况。     

核素心肌显像对骨髓干细胞移植治疗AMI的效果评价

目的探讨核素心肌显像对骨髓干细胞（MSCS）移植治疗急性心肌梗死（AMI）的效果评价。方法将48例AMI患者随机分为观察组及对照组,两组均行急诊经皮冠状动脉介入加药物治疗,观察组加行MSCS移植。治疗前后用核素心肌显像技术观察两组心功能及心肌梗死（MI）面积改善情况。结果与对照组比较,观察组心功能明显改善,MI面积明显缩小（P〈0．05）。结论MSCS移植治疗AMI的疗效显著优于常规疗法;核素心肌显像对MSCS移植前后AMI患者的疗效及预后判断有重要价值。     

核素-运动心肌灌注显像对检出急性心肌梗塞后残存缺血心肌的评估

27例无并发症的首次心肌梗塞患者,于心梗后20天至3月时进行心电图运动试验及~(99m)Tc-MIBI运动心肌灌注显像.其敏感性、特异性和准确度分别为:50%、100%; 89.42%、94.74%、77.78%、96.30%.提示~(99m)Tc-MIBI运动心肌灌注显像是评估急性心梗后梗塞区有无存活心肌的有效手段,对检出心梗后残存缺血有较大的帮助.