Data Extraction and Collection
Ultimately, there were main 3 review, 2 systematic review and meta‑analysis, 1 meta-analysis and 35 articles on evaluation of LV chamber stiffness or myocardial stiffness, including 6 studies on the ratios of echocardiographic surrogates of LV end-diastolic pressure to LV size methods, 18 on the diastolic wall strain (DWS) methods, 5 on the intrinsic velocity propagation of myocardial stretch (iVP) methods, 5 on the myocardial shear wave imaging (SWI) and 1 on the time-velocity integral (TVI) measurements of pulmonary venous and transmitral flows method. Also, data for most articles are entered into a table including echocardiographic method technique, author, year, type of study, main findings, new index statistical differences, correlation with adverse events and predictive value, receiver-operating characteristic analysis, and reproducibility (Table 2).