Background <p>All patients undergoing surgery are routinely asked to discontinue oral intake for 2&#xa0;h for water and at least 6&#xa0;h for solid foods. However, prolonged fasting can lead to intravascular volume depletion, which may impact hemodynamic stability.Tricuspid annular plane systolic excursion(TAPSE) is an echocardiographic measurement of right ventricular(RV) systolic function and may serve as an indicator of intravascular volume status. Consequently, we aimed to evaluate the effects of preoperative fasting on RV systolic function and the TAPSE in 101 patients undergoing elective surgery.</p> Methods and Methods <p>This prospective observational study included 101 patients scheduled for elective non-cardiac surgery patients without known heart disease with American Society of Anesthesiologists(ASA) physical status I–II. Transthoracic echocardiography(TTE), TAPSE, and other RV function measurements were performed when the patients were not fasting 1&#xa0;day before the surgery and all of patients didn’t nil by mouth overnight before surgery so those so they fasted for 6–12&#xa0;h on the day of surgery.</p> Results <p>TAPSE,S’, isovolumetric contraction time(IVCT), isovolumetric relaxation time(IVRT), Ejection time(ET), tricuspid peak velocity, RV end-diastolic-area(RVEDA), tricuspid E/A, RV end-systolic volume RVESV), inferior vena cava(IVC) end-of-inspiration, IVC end-of-expiration, and IVC collapsibility index were significantly different in patients who did been postprandial than in fasting patients(p &lt; 0.05 for each).</p> Conclusions <p>The TAPSE value decreased with preoperative fasting. TAPSE is influenced by changes in the volume status of the body. Because of its easy measurability, TAPSE has potential as a noninvasive marker of preoperative intravascular volume. Further studies are needed to validate its clinical applicability in perioperative hemodynamic management.</p> Trial Registration <p>NCT06105866</p>