[Changes of left ventricular systolic and diastolic function and the diagnostic value of B-type natriuretic peptide in patients with sepsis].

Objective: To explore the diagnostic value of transthoracic echocardiogram (TTE) and/or plasma B-type natriuretic peptide (BNP) for left ventricular (LV) systolic dysfunction and/or LV diastolic dysfunction in septic patients.

Methods: In this prospective observational study, 90 septic patients and 30 non-septic ones underwent serial TTEs to measure LV ejection fraction (LVEF) and blood flow velocity of mitral annulus during early diastole (E) and atrial contraction (A) ratio (E/A) within 24 h of admission, 2, 3, 5 and 7 days. Enzyme-linked immunosorbent assay (ELISA) was used to detect the plasma levels of BNP simultaneously. Patient medical records were used to obtain the information of demographics, APACHE II scores and 28-day survival rates.

Results: LVEF and E/A decreased significantly more in sepsis group (P = 0.00) while BNP elevated in sepsis group (P = 0.00). LVEF and E/A showed an initial drop and a subsequent rise. On the contrary, BNP increased and then decreased. There was a positive correlation between LVEF and E/A (r = 0.670, P = 0.00) while BNP level had a negative correlation with LVEF and E/A (r₁ = -0.733, P₁ = 0.00; r₂ = -0.929, P₂ = 0.00). Receiver operating characteristic (ROC) curve analysis showed that a cutoff point of BNP at 536.3 ng/L for diagnosing sepsis-induced LV systolic dysfunction had a sensitivity of 84.4% and a specificity of 68.7%. When at 505.0 ng/L, the valves were 56.0% and 97.4% respectively.

Conclusion: TTE may uncover septic patients whose LV diastolic dysfunction occurs earlier and reverses later than systolic type. And it may also participate in systolic dysfunction. The levels of BNP, probably as an adjustment to LV function, are more closely aligned with the severity of septic LV diastolic dysfunction. The combined application of TTE and plasma BNP appears to be efficacious for dynamically assessing cardiac function in septic patients.