Methods The clinical data of 100 patients admitted to the Second Hospital of Wuxi from 2022 to 2024 were analyzed retrospectively, including 73 males and 27 females. The age ranged from 56 to 72 years with an average of (64.35 7.18) years. According to the left ventricular ejection fraction (LVEF), patients were divided into control group (50 cases) with heart failure with reduced ejection fraction (HFrEF) and study group (50 cases) with HFpEF; at the same time, 50 patients without heart failure were selected as normal group. Three groups of patients were monitored for cardiac output (CO), cardiac index (CI), stroke rate (SV), heart rate index (SI), heart rate variability (HRV), preload [thoracic fluid conductivity (TFC), heart rate variability (SVV), vascular volume (IVV)], afterload [peripheral resistance per beat (SSVR), peripheral resistance index per beat (SSVRI), systemic resistance (SVR), vascular elasticity (VA)], myocardial contractility [left ventricular work per beat (LSW), left ventricular work per beat index (LSWI), pre ejection phase (PEP), left ventricular ejection time (VET)] using thoracic impedance spectroscopy (TEB), LVET, systolic time ratio (STR), ejection systolic index (EPCI), strain state index (ISI), and contractility variability (COPDI).
Results The LAD, STR, PEP, SSVR, and TFC values of the study group were higher than those of the normal group, while EPCI was lower than that of the normal group (P<0.05); The EPCI, LVET, LSWI, LSW, SI, SV, and CI of the control group were lower than those of the normal group, while LVDD, LAD, STR, PEP, SSVR, IVV, TFC, and HRV were higher than those of the normal group (P<0.05); The LVDD, STR, PEP, and IVV of the study group were all lower than those of the control group, while LVET, LSWI, LSW, SI, and SV were higher than those of the control group (P<0.05). After Pearson correlation analysis, STR, PEP, VA, SVR, SSVRI, SSVR, and TFC were positively correlated with the ratio of peak velocity of early diastolic blood flow (E) at the mitral valve orifice to peak velocity of early diastolic motion of the mitral annulus (e) (E/e) (P<0.05), while EPCI, LVET, LSWI, LSW, IVV, HRV, SI, SV, CI, and CO were negatively correlated with E/e (P<0.05). The ROC curve results showed that the areas under the ROC curves corresponding to STR, PEP, and TFC were 0.774, 0.808, and 0.730, respectively.
Conclusion TEB hemodynamic monitoring can help to evaluate the diastolic function of the heart, if the values of IVV, LSWI, LSW, SI and SV are in the normal range, and the values of STR, PEP and TFC are rising, it can be used to assist in the diagnosis of HFpEF.