Objective:To assess the differences of the 2016 and 2009 edtion guidelines on diastolic dysfunction in sepsis patients.Methods:A single-center, prospective study was conducted. The relevant information of sepsis patients in Intensive Care Unit (ICU) were analyzed from October 2016 to January 2019. Patients’ transthoracic echocardiography at the first 24 h and 3rd day of their admission and left ventricular diastolic dysfunction were stratified according to the 2009 and 2016 edition guidelines. Patients’ characteristics, arterial blood gas analysis, and blood biochemical indexes were recorded at the first 24 h of the ICU admission. Additionally, the following information were retrieved during ICU stay: site of infection, frequency of adrenaline and dobutamine, maximal dose of norepinephrine, use of hydrocortisone, invasive mechanical ventilation and renal replacement therapy. The rank-sum test of two independent samples was used to compare the differences in the diagnosis of left ventricular diastolic dysfunction.Results:A total of 196 patients with sepsis or septic shock were screened, and 86 patients were excluded. Finally, clinical data of 110 patients were included in the analysis.The median time of the first ultrasound examination in ICU was 17 h. Among the patients with different diastolic function severity in baseline data analysis, only age was significantly different. According to the 2016 edition guidelines, 43 (39%) of 110 patients had diastolic dysfunction and another 30 (27%) had indeterminate diastolic dysfunction within 24 h of ICU admission. According to the 2009 edition guidelines, 40 (36%) patients had diastolic dysfunction and 58 (53%) patients had indeterminate diastolic dysfunction. The diagnosis of left ventricular diastolic dysfunction of different grades was significantly different between the 2016 and 2009 edition guidelines ( Z=4.92, P<0.01). According to the 2016 edition guidelines at the 3rd day of ICU admission, 52 (47%) patients were diagnosed with diastolic dysfunction and 18 (18%) were diagnosed with indeterminate diastolic dysfunction; According to the 2009 edition guidelines, 50 (46%) of these patients were diagnosed with diastolic dysfunction and 45 (41%) had indeterminate diastolic function. Similarly, there was a large difference in diagnosis ( Z=4.60, P<0.01). Subgroup analysis of patients with normal systolic function (ejection fraction > 50%) showed that the diagnosis of left ventricular diastolic dysfunction were significantly different at the first 24 h and the 3rd day of ICU admission ( Z=4.34, P<0.01 and Z=5.71, P<0.01). Conclusions:The 2016 edition guidelines identify a significantly higher incidence of dysfunction in patients with severe sepsis and septic shock compared to the 2009 edition guidelines. Although the 2016 edition guidelines seem to be an improvement, issues remain with the application of guidelines using traditional measures of diastolic dysfunction in this cohort.