Left ventricular strain and strain rate echocardiography analysis in patients with total and subtotal occlusion in the infarct-related left anterior descending artery

Background: Numerous studies show that percutaneous coronary intervention has no clinical benefit in patients with total occlusion. Both regional and global left ventricle (LV) functions may be evaluated in detail by strain (S) and strain rate (SR) echocardiography. The purpose of this study is to evaluate whether S and SR echocardiography may be used to determine the total occlusion. Method: Sixty stable patients who have total or subtotal occlusion in the infarct‐related left anterior descending artery were enrolled (Total occlusion group: 35 and subtotal occlusion group: 25 patients). In all patients, LV longitudinal S and SR data were obtained from total 14 segments. Results: S values of middle and apical segments of LV were significantly lower in the total occlusion groups. In SR analysis, middle and apical values of all walls were significantly different between the groups. The total SR of the middle and apical segments was significantly lower in the total occlusion group (respectively, total SR in middle segments: ?3.4 ± 0.8% vs. ?4.6 ± 1.0%, P < 0.00001 and total SR in apical segments: ?1.7 ± 0.5% vs. ?2.8 ± 0.6%, P = 0.001). The total SR values of four walls were also significantly lower in the total occlusion group (?10.3 ± 2.0% vs. ?13 ± 3.1%, P < 0.0001). For predicting total occlusion, the highest sensitivity levels (84%) were obtained in SR of middle‐anterior segment. SR of middle‐septum and middle‐lateral segments has the highest specificity levels (86%). Conclusion: Total occlusion in stable patients with acute coronary syndrome has an unfavorable effect on the LV regional and global functions. Patients with total occlusion may be identified by S and SR echocardiography. (Echocardiography 2011;28:203‐209)     

应变率成像的临床应用

现综述正常心脏应变率成像表现和局部心肌缺血的特征;应变率成像定量评价局部收缩和舒张功能的可靠性;以及应变率成像结合负荷试验鉴别心肌不同存活状态等方面问题。     

Stage I hypertension is associated with impaired systolic function by strain imaging compared with prehypertension: A report from the prever study

High blood pressure (BP) is associated with higher rates of cardiovascular events, even in stage I hypertension (HTN) and prehypertension (preHTN). Lower left ventricular (LV) systolic function, assessed by global longitudinal strain (GLS), has been demonstrated in individuals with HTN compared to individuals with normal BP, but a comparison of individuals with preHTN and stage I HTN was not described to date. The PREVER study includes two randomized double‐blind controlled trials, performed in volunteers with preHTN (PREVER‐prevention trial) or stage I HTN (PREVER‐treatment trial), aged 30‐70 years. A subsample of patients of both trials had GLS measured from 2D echocardiograms performed at baseline and after 18 months of follow‐up. We compared baseline data from both studies and, among stage I HTN patients, clinical and echocardiographic correlates of GLS were determined. Participants with preHTN (n = 91;53% female; 55 ± 9 yo) and stage I HTN (n = 105; 44% female; 55 ± 8 yo) had similar clinical parameters beyond the expected differences in BP levels. Participants with stage I HTN had lower GLS (−17.5 ± 2.5% vs −18.2 ± 2.4%, P = .03) compared with those with preHTN. In stage I HTN, lower GLS was associated with lower e'' and lower LV ejection fraction. In conclusion, patients in Stage I HTN may already express changes in GLS compared with individuals with preHTN, suggesting that even mildly difference in BP can be impact in subclinical systolic function.     

Five‐year follow‐up two‐dimensional speckle tracking echocardiography in a juvenile with a double‐chambered left ventricle

Double‐chambered left ventricle (DCLV) is a particularly rare congenital entity characterized by the presence of two ventricular cavities separated by an abnormal muscle band. An asymptomatic 15‐year‐old boy was referred to our hospital because of electrocardiographic (ECG) abnormalities. His initial transthoracic echocardiography (TTE) demonstrated a DCLV with mild left ventricular systolic dysfunction. During a 5‐year follow‐up period, he remained symptom free with no changes in ECG and conventional TTE findings. However, two‐dimensional speckle tracking echocardiography revealed a subtle progressive deterioration of left ventricular systolic function during the 5‐year follow‐up.     

Regional Heterogeneity of Systolic Dysfunction Is Associated with Ventricular Dyssynchrony in Patients with Idiopathic Dilated Cardiomyopathy and Narrow QRS Complex

Background: Regional heterogeneity of left ventricular (LV) contraction, known as dyssynergy, in idiopathic dilated cardiomyopathy (IDC) patients has been previously reported, but no comprehensive analysis of this abnormality has been made. The purpose of this study was to test the hypothesis that regional heterogeneity of systolic dysfunction is associated with LV dyssynchrony in IDC patients with a narrow QRS complex using novel three‐dimensional (3D) speckle‐tracking strain. Methods: We studied 54 consecutive IDC patients with ejection fraction (EF) of 34 ± 12% and QRS duration of 102 ± 13 msec (all <120 msec), and 30 age‐matched normal controls. The 3D speckle‐tracking LV dyssynchrony (LV dyssynchrony index) was quantified from all 16 LV sites to determine the standard deviation (SD) of time‐to‐peak strain. Similarly, regional heterogeneity of LV systolic function (LV dyssynergy index) was quantified from all 16 LV sites to establish the SD of peak 3D speckle‐tracking strain. Results: The LV dyssynergy and dyssynchrony indices of IDC patients were significantly larger than those of normal controls. Furthermore, IDC patients showed significantly higher Z‐scores for septum and inferior regions than for the free wall (3.34 ± 1.21 vs. 1.69 ± 1.06 and 2.79 ± 1.30 vs. 1.69 ± 1.06, respectively, P < 0.001). An important findings of multivariable analysis was that the LV dyssynergy index (β = 0.69, P < 0.001) and LVEF (β = ?0.34, P = 0.001) were independent determinants of the LV dyssynchrony index. Conclusion: 3D speckle‐tracking strain revealed that the myocardial systolic dysfunction of IDC patients with a narrow QRS complex has a marked heterogeneous regional distribution. This regional heterogeneity as well as systolic dysfunction is thought to lead to LV dyssynchrony.     

Two-dimensional acoustic pattern derived strain parameters closely correlate with one-dimensional tissue Doppler derived strain measurements.

BACKGROUND: Two-dimensional strain echocardiography (2D-SE) calculates tissue velocities via frame-to-frame tracking of unique acoustic markers within the image and provides strain parameters in two dimensions. Novel 2D-SE software allows semi-automated strain measurements and increased averaging capabilities optimizing signal-noise ratio. AIM: We tested whether 2D-SE and the currently used and well-validated tissue Doppler derived strain echocardiography (TD-SE) yield similar information in the clinical setting. METHODS AND RESULTS: We performed 2D-SE and TD-SE on 17 patients with amyloid cardiomyopathy and 10 age-matched healthy volunteers. Single walls from standard apical views (2- and 4-chamber) were acquired at high frame rates ( approximately 200fps). Offline analysis was performed by observers blinded to clinical data using the EchoPAC program with custom 2D-SE software. Longitudinal strain rate and strain from the basal, mid and apical segments of the septal and lateral walls were determined by each method (TD-SE and 2D-SE). Ejection fraction was >0.55 in healthy volunteers and ranged from 0.30 to 0.80 in cardiomyopathy group. A total of 54 walls (162 segments) were examined. Acceptable quality strain data was available in 92% and 85% segments by 2D-SE and TD-SE, respectively. Two-dimensional strain echocardiography values correlated closely with TD-SE values (r=0.94 and 0.96 for strain rate and strain, respectively). CONCLUSIONS: Deformation analysis by 2D-SE is feasible in a clinical setting and 2D-SE values correlate closely with TD-SE measurements over a wide range of global systolic function. Two-dimensional strain echocardiography may help to facilitate the routine clinical implementation of deformation analysis.     

Efficacy of longitudinal speckle tracking strain in conjunction with isometric handgrip stress test for detection of ischemic myocardial segments

Background: Isometric handgrip stress test is a simple method for detecting coronary artery disease (CAD). However, the value of this method alone is limited by relatively low sensitivity. This study thus aimed to investigate the usefulness of two‐dimensional speckle‐tracking strain combined with handgrip for CAD patients. Method: We studied 35 patients with stable angina pectoris who underwent percutaneous coronary intervention (PCI). Longitudinal (L‐?) and transverse peak systolic (T‐?) strains were measured from three standard apical views before and 1 month after PCI. Segments corresponded to perfusion territories of coronary arteries were divided into two groups based on coronary angiography results: stenotic (S) and nonstenotic (NS) segment. Results: L‐? in S segments increased significantly after PCI, from ?15.8% to ?17.6% (P < 0.01), but not in NS segments. Moreover, L‐? in S segments increased significantly during handgrip before PCI, from ?15.8% to ?17.6% (P < 0.01), but decreased after PCI, from ?17.6% to ?16.7% (P = 0.02). In contrast, L‐? in NS segments decreased significantly during the isometric handgrip stress test before and after PCI (P < 0.05). Especially noteworthy is that a relative change in L‐? of >1.2% during handgrip before PCI could detect significant coronary stenosis with a sensitivity of 80%, specificity of 66%, and area under the curve of 0.77 (P < 0.001). On the other hand, no significant changes were observed in either T‐? segments during handgrip either before or after PCI. Conclusion: Longitudinal speckle‐tracking strain combined with handgrip may constitute a valuable tool for detection of ischemic myocardial segments and prediction of improvement of regional contraction after revascularization. (Echocardiography 2012;29:411‐418)     

超声心动图应变和应变率成像的临床应用新进展

超声心动图应变和应变率成像是一种评估心肌功能的新技术。源于组织多普勒和二维斑点跟踪的应变和应变率对及早发现心肌功能障碍具有很高的敏感性。这些新的非侵入性诊断方法能够区分节段心肌的主动和被动运动,量化心室内的收缩不同步和评估部分心肌功能,因此,其潜在的临床应用范围非常广泛,包括存活心肌的评价和早期发现不同病因的心脏疾病等。此外,应变和应变率的数据还提供了重要的预后信息。综述阐述了源于组织多普勒、斑点跟踪二维应变成像的应变和应变率的基本概念,并讨论了这些新的超声方法主要的临床应用以及这些技术存在的局限性和发展前景,这些都是目前国内外心血管超声研究的热点之一。     

Evaluation of left atrial function in patients with coronary artery disease by two-dimensional strain and strain rate imaging

Background: Left ventricular (LV) dysfunction in patients with coronary artery disease is shown by strain and strain rate imaging. However, left atrium (LA) function in patients with coronary artery disease (CAD) has not been assessed by this method. Methods and Results: In 34 CAD patients, including 17 patients with enlarged LA (LA diameter ≤ 4.0 cm) and 17 with normal‐size LA (LA diameter ≤ 4.0 cm), two‐dimensional strain echocardiographic imaging (2DSE) was performed. Twenty healthy subjects as a control group were included. Both conventional parameters and strain parameters, such as LA peak systolic strain (LAs S/SR), preatrial contraction strain (LAa S), peak systolic (LAs SR), early diastolic strain rate (LAe SR) and late diastolic strain rate (LAa SR), were measured. Conventional parameters were abnormal in CAD patients with enlarged LA (ELA), but there were no significant differences between CAD with normal‐size left atrium (NLA) and control groups. LAs S/SR and LAe SR were lower in patients than in normal controls, and were even lower in CAD‐ELA group (P < 0.05). LAa S/SR were lower in CAD patients with ELA (P < 0.05), but without a significant difference between CAD‐NLA and control groups. A significant correlation was observed between LAs S/SR and LA emptying fraction (r = 0.85, P < 0.05; r = 0.72, P < 0.05, respectively). LAa S/SR related well to LA ejection fraction (r = 0.68, P < 0.05; r = 0.61, P < 0.05, respectively). LAs SR was most accurate in identifying both CAD patients with NLA from controls and CAD patients from controls (area under the curve: 0.91; 0.95, respectively). Conclusions: LA diastolic dysfunction occurs prior to LA systolic dysfunction in CAD patients, and LAs SR is the most accurate index in identifying patients with CAD. (Echocardiography 2011;28:1095‐1103)