Comparison of Left Ventricular Systolic Function Quantification Using Contrast-Enhanced and Non-Contrast Echocardiographic Images

Abstract

Background: Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) are two important index for the quantification of left ventricular systolic function. With the help of ultrasound contrast agents, we can improve the definition of endocardial borders and allow the quantification of LVEF in patients with poor image quality. However, the feasibility of GLS measurements in contrast-enhanced images is still controversial. Our study aimed to explore the feasibility of GLS measured by velocity vector imaging (VVI) in contrast-enhanced images, compare the difference of measurements in contrast-enhanced and non-contrast images, and analyze the relation between LVEF and GLS in both conditions.Methods: A total of 133 patients with cancer, who were registered for transthoracic echocardiography as well as contrast-enhanced echocardiography were studied. LVEF was measured using the biplane modified Simpson’s rule and GLS was measured with offline VVI analysis of the three standard apical views in non-contrast and contrast-enhanced images respectively. Linear regression was performed to derive correlation coefficients between LVEF and GLS both in non-contrast and contrast-enhanced images.Results: GLS measurements in non-contrast images were discarded in 2/133 patients (1.5%), while in contrast-enhanced images were obtained in all patients. LVEF (64.12B7.47% vs. 66.25a8.61%, respectively; P < 0.01) and GLS (-20.99c4.67% vs. -23.40k4.58%, respectively; P < 0.01) were both significantly higher in the presence of contrast agents. A linear regression between LVEF and GLS in non-contrast images (r=0.627, P<0.001) was observed, as well as in contrast-enhanced images (r=0.649，P<0.001).Conclusion: GLS measured by VVI in contrast-enhanced echocardiography is a feasible and reliable index for the quantification of left ventricular systolic function, even in patients with poor image quality. Compared with the measurements in non-contrast images, both LVEF and GLS measurements are higher in the presence of contrast agents.