From the Guidelines
The key measures of left ventricular (LV) systolic function according to the American Society of Echocardiography (ASE) guidelines are left ventricular ejection fraction (LVEF), which can be estimated or calculated, and the qualitative description of left ventricular systolic function, including categories such as normal, hyperdynamic, mildly reduced, moderately reduced, severely reduced, or unknown. These measures are crucial for assessing the systolic function of the left ventricle, with LVEF being defined as the proportion of blood ejected during left ventricular contraction of the heart, and can be calculated using the formula: LVEF = ([EDV-ESV]/EDV) * 100, as noted in the study by 1.
The ASE guidelines emphasize the importance of LVEF, with normal values typically considered to be above 55%, and categories of reduction including mildly, moderately, and severely reduced, as outlined in the study by 1. The guidelines also discuss the qualitative description of left ventricular systolic function, which may include integration of visual assessment and quantitative measures, as seen in the study by 1.
Additional parameters that can be used to assess LV systolic function include left ventricular outflow tract diameter at mid-systole, which is a quantitative measurement of the mid-systolic diameter of the left ventricular outflow tract, as discussed in the study by 1. However, the most recent and highest quality study, 1, prioritizes LVEF and the qualitative description of left ventricular systolic function as the key measures.
It is essential to use multiple parameters rather than relying on a single measure to provide a comprehensive assessment of LV systolic function, particularly in patients with borderline LVEF or those with preserved LVEF but suspected heart failure, as emphasized in the guidelines and study by 1. The use of various echocardiographic techniques, including 2D, 3D, M-mode, and speckle tracking, can help obtain these measurements, as discussed in the study by 1.
In clinical practice, prioritizing the assessment of LVEF and the qualitative description of left ventricular systolic function, as recommended by the ASE guidelines and the study by 1, is crucial for evaluating morbidity, mortality, and quality of life outcomes in patients with suspected or known left ventricular systolic dysfunction.
From the Research
Key Measures of Left Ventricular Systolic Function
The American Society of Echocardiography (ASE) guidelines emphasize the importance of assessing left ventricular (LV) systolic function through various echocardiographic measures. The key measures include:
- Left ventricular ejection fraction (LVEF), which is the most validated and commonly used measure of systolic function 2
- Global longitudinal strain (GLS) from speckle tracking echocardiography (STE), which is a sensitive and feasible method that overcomes many of the limitations of LVEF 2, 3, 4
- Forward ejection fraction, which is the forward stroke volume relative to LV end-diastolic volume 3
- Speckle-tracking global longitudinal strain (GLS), which characterizes myocardial deformation and is more sensitive to left ventricular dysfunction than LVEF 3, 4, 5
Advantages of Global Longitudinal Strain
GLS has several advantages over LVEF, including:
- Improved reproducibility, with a higher intra-class correlation coefficient (ICC) compared to LVEF 5
- Ability to detect further impairment in LV systolic function in patients with severe secondary mitral regurgitation 3
- Potential to improve risk stratification, redefine criteria for disease classification, and determine treatment in asymptomatic left ventricular dysfunction resulting from various etiologies 4
- Utility across the spectrum of heart failure and in the evaluation of valvular heart disease 4
Echocardiographic Parameters of LV Systolic Function
Other echocardiographic parameters that can be used to assess LV systolic function include: