Objective:To discuss the quantitative evaluation of left ventricular systolic function in patients with light-chain amyloidosis (AL) by pressure-strain loop (PSL).Methods:Forty-six patients with clinically diagnosed as AL in the Affiliated Tumor Hospital of Zhengzhou University from January 2018 to December 2020 were selected as case group, and they were divided into 2 groups according to whether the thickness of interventricular septum and posterior wall at end-diastole was >12 mm; ①cardiac amyloidosis (CA) group (21 cases, the thickness>12mm); ②non cardiac amyloidosis (NCA) group (25 cases, the thickness≤12 mm). Twenty five healthy volunteers were selected as control group at the same time. Routine echocardiography was performed in all subjects.Two-dimensional dynamic images of the left ventricular apical two-chamber, three-chamber, and four-chamber views were collected for three consecutive cardiac cycles using two-dimensional speckle-tracking. A tracing analysis was conducted and blood pressure was entered on the off-line Echo PAC 203 software, and the left ventricular global longitudinal strain (GLS), peak strain time dispersion(PSD), global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE) were obtained. The differences of GLS, PSD and myocardial work (GWI, GCW, GWW, GWE) parameters were compared between groups, and Pearson correlation was used to analyze the correlations.Results:①Routine echocardiography: Compared with the control group and NCA group, inter-ventricular septum thickness (IVST), left ventricle posterior wall thickness (LVPWT), left ventricular mass index (LVMI), left atrial diameter (LAD), and E/e′ in CA group were increased, while left ventricular ejection fraction (LVEF) was decreased; ②Compared with the control group, GLS, GWI, and GCW in NCA group were decreased, while there were no statistically differences in GWE, PSD, and GWW between the two groups (all P>0.05); Compared with the control group and NCA group, GLS, GWI, GCW, and GWE were obviously decreased, while PSD and GWW were obviously increased in CA group.③ Correlation analysis showed that: the absolute value of GLS was positively correlated with GWI, GCW and GWE ( r=0.654, 0.695, 0.788; all P<0.001), and negatively correlated with GWW, and PSD ( r=-0.710, -0.625; all P<0.001). Besides, PSD had negative correlation with GWI, GCW and GWE ( r=-0.754, -0.653, -0.702; all P<0.001), and positive correlation with GWW ( r=0.676, P<0.001). Conclusions:PSL can quantitatively evaluate the left ventricular systolic function of AL patients, while the myocardial work parameters are conducive to evaluate the degree of cardiac involvement in the course of AL patients.