The Value B-natriuretic Peptide Levels And Tissue Dopplerlmaging In The Evaluation Of Left VentricularDysfunction

Objective To explore the value of plasma B-natriuretic peptide(BNP) levels and tissue Doppler imaging (TDI) in the evaluation of left ventricular dysfunction,and to evaluate the ability of predicting ventricular dysfunction by plasma BNP levels.Methods Echocardiography with color-coded DTI was performed in 111 hospital patients for assessment of systolic and diastolic function.Systolic dysfunction is determined if the jection fraction(EF) is reduced(EF﹤50%)in patients with congestive heart failure(CHF),Diastolic dysfunction is determined if EF is normal(EF≥50%)in patients with CHF.Diastolic function was categorized according to the progression of diastolic dysfunction :normal,impaired relaxation,pseudonormal filling and restrictive filling.The studying population was categorized according to the echocardiography recording:normal(n=30),systolic dysfunction (n=29),diastolic dysfunction(n=52). Plasma BNP levels were measured by a Enzyme-Linked Immunosorbent Assay, and were used for the assessment of LV function. the cutoff valule of plasma B-natriuretic peptide(BNP) levels in the evaluation of left ventricular dysfunction is evaluated.Result The systolic (Sm) velocities,early diastolic (Em) velocities of mitral annalas and E/Em in patients with SD were significantly lower than in patients with DD and control(Sm : 3.32±1.31,6.01±1.62,5.90±0.91,respectively p﹤0.001;Em:3.36±2.02,4.72±2.16,7.48±1.75,respectively, p﹤0.05;E/Em:28±11,15±7,10±3,respectively ,p﹤0.001 ), There are no difference in Sm,Em,E/Em between patients with DD and control, The area under the receiver-operating characteristic curve for Sm to detect EF(ejection fraction)﹤50% was 0.925.The optimal cutoff value was 4.6cm/s,The sensitivity,specificeity of Sm in prediction of EF﹤50% were 90.5%,87.4%,respectively.Mean plasma BNP levels in patients with DD was higher compred with control group(357.65±278.49,192.78±182.71; p﹤0.01), The DD patients'mean concentration of BNP was higher than control(192.78±182.71 vs 94.46±78.83;p﹤0.05), Patients with restrictivelike filling patterns on echocardiography had the highest BNP levels in patients with DD(565.50±265.79pg/ml,256.11±222.18pg/ml,193.67±174.51pg/ml;p﹤0.001);Plasma BNP levels were significantly correlated with Sm,Em and E/Em; The area under the receiver-operating curve for BNP to detect EF﹤50% was 0.75; The area under the receiver-operating curve for BNP to detect E/Em﹥15 was 0.858, The sensitivity, specificity of for BNP﹥141pg/ml in predicting of E/E﹥15 were 81.8%,82.1% .Conclusion 1) TDI can accurately evaluate the SD and restrictive filling patterns of left ventricular,and discriminate the pseudonormal patterns in patients with DD from normal diastolic function;2) BNP can reliably detect the presence of left ventricular systolic,diastolic dysfunction on TDI,In patients with normal systolic function, elevated BNP levels might help to reinforce the diagnosis of diastolic dysfunction;3)the combination of BNP levels along with TDI may be a comprehensive predictor of heart function in patients with suspected left ventricular dysfunction.