A Practical Approach to Using Strain Echocardiography to Evaluate the Left Ventricle

Abstract

Circulation Journal Official Journal of the Japanese Circulation Society http://www. j-circ.or.jp valuation of left ventricular (LV) systolic function is a critical component of the practice of cardiology and a fundamental function of the echocardiographic examination. Although LV systolic function is commonly defined by ejection fraction (EF), there are numerous technical and hemodynamic limitations to EF. A qualitative "eyeball" estimate has high variability, and quantitative measurements are subject to endocardial border definition and formulas that make assumptions in geometry of the LV. The EF denotes global LV function and does not convey any regional differences in function that may exist in patients with various cardiomyopathies. Hyperkinetic segments can distort a global measurement, leading to an underestimation of the significance of regional abnormalities. There are several alternative techniques that can either supplement or replace EF, including tissue Doppler recordings of the mitral annulus and measurements such as the TEI or myocardial performance index. Doppler-Derived Strain RateThe newest technique for evaluating the LV uses the concept of strain or strain rate. This technique assesses myocardial mechanics by measuring the relationship between 2 points within the myocardium as if they were connected by a rubber band. When the 2 points move away from each other (myocardial lengthening during diastole), strain values are positive. When the 2 points move toward each other (myocardial shortening during systole), strain is decreased, generating negative strain. Strain and strain rate can be derived from either tissue Doppler or speckle tracking 2-or 3-dimensional (D) echocardiography. Using tissue Doppler, which is a form of pulsed Doppler, specific points within the myocardium can be identified. 1 Tracking these Doppler points enables measurement of strain rate. Because Doppler is velocity or distance divided by time, the initial measurement is strain rate. Integrating the strain rate gives strain.There are limitations to the Doppler-based strain rate. As with all Doppler applications, the Doppler-derived strain rate is angledependent. The Doppler strain rate sample volume is also fixed while the myocardium is moving. Thus the sample volume may not stay within the myocardium throughout the cardiac cycle. Strain rate is a derivative of strain and tends to be noisy. Figure 1 shows one way of recording strain rate using "curved M-mode". A resting normal 4-chamber view shows yellowishbrown strain rate during ventricular systole. The strain rate recording of the apex is not reliable, because the apex is perpendicular to the ultrasonic beam, so there is no Doppler signal. With exercise the systolic strain rate turns reddish brown, indicating a higher degree of negativity or contraction in the basal segments. This patient has a blockage in the left anterior descending coronary artery. With exercise, there is a delay in the onset of contraction of the apical half of the septal and lateral walls, a failur...

Left ventricular function after takotsubo is not fully recovered in long-term follow-up: A speckle tracking echocardiography study

“…This method relies only on two planes and is based on mathematical assumption. Furthermore, it does not yield the complexity of LV mechanics even when supported by 3D acquisition [6,[36][37][38]. In our study, no significant differences in traditional echocardiographic parameters of a systolic and diastolic function of LV were observed.…”

“…Several studies have reported complete recovery of LV systolic function in patients with TTC as analyzed by the LV ejection fraction (LVEF) during follow-up [1][2][3]. Two-dimensional speckle tracking echocardiography (2D STE) is a valuable tool to evaluate global and regional LV function and appears to be more precise and distinctive than traditional echocardiography for detecting subtle myocardial abnormalities [4][5][6]. Apical and basal LV rotation have been described as an important part of LV twist, which plays a key role in maintaining both systolic and diastolic function [5][6][7][8].…”

“…Two-dimensional speckle tracking echocardiography (2D STE) is a valuable tool to evaluate global and regional LV function and appears to be more precise and distinctive than traditional echocardiography for detecting subtle myocardial abnormalities [4][5][6]. Apical and basal LV rotation have been described as an important part of LV twist, which plays a key role in maintaining both systolic and diastolic function [5][6][7][8]. LV untwisting parameters have been used to quantify LV diastolic function by 2D STE [5,8].…”

“…This method analyzes myocardial velocities and deformations and is, therefore, useful in assessing LV systolic and diastolic function [5,6,[39][40][41][42]. 2D STE has, in previous studies, been used to assess the functional recovery of LV systolic function after the acute phase of TTC.…”

Echocardiographic assessment of myocardial ischemia

“…The first clinical use was suggested as early as 2003 (86), and today, further standards for the analyses of left myocardial function are being proposed (65). The use of apical views for the evaluation of cardiac deformation seems to be clinically useful (87), and apical views result in the best reproducibility (88). Analyses of systolic regional deformations (Figure 8), the diastolic properties in CHD, estimations of LV filling and left atrial function (73) are further advantages of this technology.…”