From the Guidelines
Assessing systolic function with transthoracic echocardiography (TTE) involves obtaining standard imaging views, calculating left ventricular ejection fraction (LVEF), evaluating wall motion abnormalities, and measuring additional parameters such as global longitudinal strain (GLS) and tissue Doppler imaging. To assess systolic function with TTE, the following steps should be taken:
- Obtain standard imaging views including parasternal long-axis, parasternal short-axis, apical four-chamber, apical two-chamber, and apical three-chamber views.
- Calculate LVEF using either the biplane Simpson's method of discs or the modified Quinones method, as recommended by the 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy 1.
- Evaluate wall motion abnormalities using the 17-segment model, scoring each segment as normal, hypokinetic, akinetic, or dyskinetic.
- Measure stroke volume using the LVOT diameter and LVOT VTI (velocity time integral).
- Assess additional parameters such as GLS, which can detect subtle systolic dysfunction before LVEF decreases, and tissue Doppler imaging to measure the S' velocity at the mitral annulus, as suggested by the ACR Appropriateness Criteria for suspected new-onset and known nonacute heart failure 1.
- For right ventricular function, assess TAPSE (tricuspid annular plane systolic excursion), RV S', and FAC (fractional area change). These measurements collectively provide a comprehensive evaluation of cardiac systolic function, with LVEF values above 55% generally considered normal, 45-54% mildly reduced, 30-44% moderately reduced, and below 30% severely reduced. The use of advanced echocardiographic techniques, such as speckle tracking and strain rate imaging, can provide additional insights into systolic function and help identify high-risk patients, as noted in the ACR Appropriateness Criteria 1.
From the Research
Steps to Assess Systolic Function with TTE
To assess systolic function using Transthoracic Echocardiography (TTE), several parameters and techniques can be employed. The steps involve:
- Measuring Left Ventricular Ejection Fraction (LVEF) as a basic indicator of global systolic function 2, 3, 4, 5.
- Evaluating Left Ventricular (LV) longitudinal function, which can be expressed through parameters such as Mitral Annular Plane Systolic Excursion (MAPSE) 2, 6.
- Utilizing speckle-tracking echocardiography to measure Global Longitudinal Strain (GLS), which provides a more sensitive assessment of LV systolic function than LVEF alone 3, 6, 5.
- Considering the use of 3D echocardiography for more accurate and reproducible measurements of LV volumes and LVEF 5.
- Assessing LV torsion and myocardial work for a comprehensive evaluation of systolic function, especially in cases where traditional parameters may not fully capture the extent of dysfunction 4, 5.
Parameters for Systolic Function Assessment
Key parameters include:
- LVEF: A traditional and widely used measure, though it has limitations in certain pathophysiological conditions 2, 3, 4, 5.
- MAPSE: Useful for evaluating longitudinal function, particularly in patients with poor sonographic windows or as a complementary measure to EF 2, 6.
- GLS: Derived from speckle-tracking echocardiography, offering higher sensitivity for detecting LV dysfunction and providing prognostic information 3, 6, 5.
- Myocardial strain and work: Newer techniques allowing for the assessment of contractility independent of afterload effects and detection of specific myocardial pathologies 5.
Clinical Application
These parameters and techniques are applicable in various clinical scenarios, including:
- Monitoring asymptomatic cardiotoxicity related to chemotherapy, where GLS has been proposed as a preferred method 3.
- Evaluating valvular heart disease and heart failure, where a comprehensive assessment of systolic function can guide management and prognosis 3, 4, 5.
- Detecting early signs of LV systolic dysfunction in patients with hypertension or aortic stenosis, among other conditions 2, 6.