LV Mechanics in Mitral and Aortic Valve Diseases: Value of Functional Assessment Beyond Ejection Fraction

The assessment of myocardial function in the context of valvular heart disease remains highly challenging. The myocardium deforms simultaneously in 3 dimensions, and global left ventricular (LV) function parameters such as volume and ejection fraction may remain compensated despite the changes in myocardial deformation properties. Current guidelines recommend valve replacement/repair in the presence of symptoms or reduced LV ejection fraction, but the resolution of symptoms or recovery of LV function post-surgery may not be reliably predicted. A wealth of evidence currently suggests that LV dysfunction is frequently subclinical despite normal ejection fraction. It may precede the onset of symptoms and portend a poor outcome due to progressive myocardial remodeling and dysfunction during the post-operative period. The advent of novel tissue-tracking echocardiography techniques has unleashed new opportunities for the clinical identification of early abnormalities in LV function. This review gathers and summarizes current evidence regarding the use of these techniques to assess myocardial deformation in patients with valvular heart disease.     

Three-dimensional speckle-tracking echocardiography: methodological aspects and clinical potential

Speckle-tracking echocardiography (STE) is an advanced echocardiographic technique that allows a novel approach to the assessment of cardiac physiology through the study of myocardial mechanics. In its three-dimensional (3D) modality, it overcomes the drawbacks inherent to other echocardiographic techniques, namely two-dimensional echocardiography and tissue Doppler imaging. Several research studies and software improvements have led 3D-STE to become a promising tool for accurate evaluation of global and regional cardiac function. This article addresses the image acquisition, analytical methods, and parameters of myocardial mechanics that could be derived from 3D-STE. This systematic guidance may help to establish its usefulness in the global and regional evaluation of cardiac function, and to facilitate its clinical application.     

Early detection of left ventricular systolic dysfunction using two-dimensional speckle tracking strain evaluation in healthy subjects after acute alcohol intoxication

Objectives: We evaluated the ability of two-dimensional speckle tracking strain echocardiography to detect left ventricular (LV) systolic dysfunction as compared with LV ejection fraction (EF) in healthy subjects following acute alcohol intoxication. Methods and Results: In total, 25 healthy subjects were investigated using echocardiography 4-6 hours after the onset of alcohol intoxication at a regional festive gathering, and then compared to 23 healthy control subjects without alcohol consumption. Heart rate, blood pressure, blood alcohol level, LV volumes, EF, shortening fraction, E/A ratio, as well as global longitudinal strain (LS) were recorded. Mean blood alcohol level was 1.3 ± 0.3 g.L(-1) . Mean systolic blood pressure and heart rate were slightly increased in the alcohol group compared to controls (147.5 ± 21.8 mmHg vs 127.0 ± 9.9 mmHg, P = 0.003, and 79.7 ± 10.7 bpm vs 70.6 ± 7.6 bpm, P < 0.001, respectively). While there was no significant difference in terms of LVEF (62.9 ± 4.4% vs 64.8 ± 5.9%, P = 0.18) or shortening fraction (34.7 ± 5.9% vs 36.0 ± 4.3%, P = 0.54), global LS was significantly impaired (-17.8 ± 2.0% vs -21.2 ± 1.8%, P < 0.001). In addition, subjects who consumed alcohol had increased LV end-diastolic (108.3 ± 20.1 mL vs 95.5 ± 14.6 mL, P = 0.037) and end-systolic volumes (41.6 ± 11.4 mL vs 33.7 ± 6.9 mL, P = 0.024), along with depressed aortic time-velocity integral (19.9 ± 3.2 mL vs 21.9 ± 2.5 mL, P = 0.034). According to multivariate linear regression analyses, blood alcohol level was the only factor significantly associated with global LS (β=-3.6 ± 1.0, P = 0.005). Conclusion: Alcohol intoxication around festive days induces acute LV contraction abnormalities, which may be detected using global LS by speckle tracking at an earlier stage and more accurately than LVEF decreases.     

Reference values of right atrial longitudinal strain imaging by two-dimensional speckle tracking

Background: The role of speckle tracking in the assessment of right atrial (RA) deformation dynamics has not been established yet. The reference ranges of RA longitudinal strain indices were measured by speckle tracking in a population of normal subjects. Methods: In 84 healthy individuals, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and time to peak longitudinal strain (TPLS) were measured using a six‐segment model for the RA. Strain rate (SR) was also measured starting from the QRS‐wave onset, peak positive (x‐wave), first peak negative (y‐wave), and second negative peak (z‐wave). The time from the QRS onset was measured to each wave peak. Results: Adequate tracking quality was achieved in 64% of segments analyzed. Inter‐ and intraobserver variability coefficients of measurements ranged between 6% and 11%. Global PALS was 49 ± 13%, global TPLS was 363 ± 59 msec, x‐wave was 2.12 ± 0.58 sec^?1, y‐wave was ?1.91 ± 0.63 sec^?1, and z‐wave was ?2.18 ± 0.78 sec^?1. Conclusion: Speckle tracking is a feasible technique for the assessment of longitudinal myocardial RA deformation. Reference ranges of strain indices were reported. (Echocardiography 2012;29:147‐152)     

斑点追踪技术评价左室扭转及解旋运动的临床应用

近几年,斑点追踪技术在国内已初步应用于临床,且取得了一定的成果,如评价心功能、心脏再同步化治疗及起搏治疗前后指导以及冠心病、心肌病、瓣膜性心脏病等疾病的诊断与治疗效果。本文从上述几方面做一综述,以促进其在临床工作中的进一步应用及发展。     

Three-dimensional speckle-tracking echocardiography for evaluating myocardial motion in patients with cardiorenal syndrome

Because of better awareness and understanding of its pathophysiology, the cardiorenal syndrome (CRS) is more often diagnosed and better managed. The echocardiographic evaluation of CRS now benefits from three-dimensional speckle tracking echocardiography (3D-STE), which allows multidimensional and real-time evaluation of regional myocardial and overall cardiac function, and helps assessing the degree of myocardial damage. This article describes the application of 3D-STE in evaluating the myocardial motion in patients with CRS.