Abstract：Objective To explore the clinical value of heart rate variability(HRV) and echocardiography in making diagnosis and prognostic evaluation among heart failure patients with preserved ejection fraction. Methods A total of 144 patients with normal left ventricular ejection fraction(LVEF) underwent 24hour ambulatory electrocardiography and routine echocardiography examinations. Patients were divided into two groups according to echocardiography results: left ventricular diastolic dysfunction(LVDD) group(LVDD group, 76 cases) and normal left ventricular diastolic function(LVDF) group(normal LVDF group, 68 cases). According to the receiver operating characteristic(ROC) curve, the diagnostic significance of HRV on LVDD was analyzed, and the primary endpoint events were followed up. Results Among HRV indexes, the area under curve of 24-hour standard deviation of NN intervals(SDNN) in the prediction of LVDD is the largest (AUC=0.827，P<0.01); the cut-off value is 92 ms. According to the cut-off value, the patients in LVDD group are further divided into two groups: low-SDNN group(cut-off value<92 ms, 40 cases) and high-SDNN group (cut-off value≥92 ms, 36 cases). The survival curve reveals that in the low-SDNN group the incidence of adverse cardiac events and total mortality are significantly higher than those in the high-SDNN group(P<0.05). Conclusion SDNN can be served as a sensitive indicator for making clinical diagnosis and prognostic evaluation among the patients with LVDD.
