Objectives: To assess the ability of left atrial(LA) strain parameters to discriminate patients with elevated left atrial pressure(LAP) from patients with atrial fibrillation(AF). Methods and results: A total of 142 patients with non-valvular AF who underwent first catheter ablation(CA) between November 2022 and November 2023 were enrolled in the study. Conventional and speckle-tracking echocardiography（STE）were performed in all patients within 24 hours before CA，and LAP was invasively measured during the ablation procedure. According to mean LAP,the study population was classified into 2 groups of normal LAP(LAP＜ 15 mmHg, n=101) and elevated LAP（LAP≥15 mmHg, n=41)．Compared with the normal LAP group, elevated LAP group showed significantly reduced LA reservoir strain (LASr) [9.14 ( 7.97 -11.80 ) vs 20(13.59-26.96), p < 0.001], and increased LA filling index[9.60 ( 7.15 -12.20 ) vs 3.72 ( 2.17 -5.82 )，p<0.001], LA stiffness index[1.13 ( 0.82-1.46 ) vs 0.47( 0.30 -0.70 )，p<0.001]. LASr, LA filling index and LA stiffness index were independent predictors of elevated LAP after adjusted by the type of AF, EDT, E/e’, mitral E and Peak acceleration rate of mitral E velocity. The receiver-operating characteristic curve (ROC) analysis showed LA strain parameters (area under curve [AUC] 0.794 to 0.819) could provide similar or greater diagnostic accuracy for elevated LAP, as compared to conventional echocardiographic parameters. Furthermore, the novel algorithms built by LASr, LA stiffness index, LA filling index and LA emptying fraction（LAEF）, was used to discriminate elevated LAP in AF with good accuracy (AUC 0.880, accuracy of 81.69%, sensitivity of 80.49%, specificity of 82.18%), and much better than 2016 ASE/EACVI algorithms in AF. Conclusion: In patients with AF，LA strain parameters could be useful to predict elevated LAP and non-inferior to conventional echocardiographic parameters. Besides, the novel algorithm built by LA strain parameters combined with conventional parameters would improve the diagnostic efficiency.

ABSTRACT Background: Conventional echocardiography identifies STEMI by regional wall motion abnormality (RWMA), but it still has a great challenge to identify other types of coronary artery disease (CHD). The Two-dimensional Speckle Tracking Echocardiography (2D-STE) makes up for some of the deficiency, especially by using the myocardial work which combined with the left ventricular pressure condition. By this way, the dysfunctional region of myocardium can be identified more accurately, which is expected to be a new non-invasive prediction method for CHD. Methods: According to the exclusion criteria, 140 patients who had received coronary angiography (CAG) were included in this study. According to the stenosis rate of coronary artery, the patients were divided into CHD group and control group. The predictive efficacy of GLS and GWI for severe coronary artery stenosis were compared by ROC curve. Then, the 140 patients were respectively re-grouped according to the stenosis rate of LAD, LCX and RCA three times. The regional GLS and GWI are recorded as GLS R and GWI R according to the PRI method described in this article. The efficacy of GLS R and GWI R in predicting severe coronary artery stenosis were compared. Certainly the prediction efficiency between PRI method and traditional method (using the value of GLS and GWI directly) were also compared. Results: In predicting severe coronary artery stenosis, compared with GLS R, GWI R showed significantly higher sensitivity (95.2% vs 70.2%) and similar specificity (87.5% vs 91.1%). In the aspect of identification of certain coronary artery with severe stenosis, the sensitivity of GWI R was significantly higher than GLS R in predicting severe stenosis of LAD, LCX, and RCA (LAD: 96.5% vs 64.9%; LCX: 65.6% vs 50.0%; RCA: 50% vs 20%). Compared with traditional method, the “positive region identification” method has higher AUC in the ROC curve. Conclusion: GWI is more sensitive than GLS in identifying patients with CHD that couldn’t be detected by conventional echocardiography and performs better in accurately disclosing the culprit coronary arteries with severe stenosis. Compared with the traditional method, the PRI method can be used to judge whether there is severe stenosis in any coronary artery more accurately and confidently. Keywords: echocardiography, speckle-tracking echocardiography, pressure-strain loop, myocardial work, global longitudinal strain, coronary artery disease, coronary artery stenosis