Introduction :There are frequent discrepancies between B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NP-BNP)in individual patients and mutiple factors might play a role to this discordance. This study was designed to compare the efficacy of screening in diagnosis of LV dysfunction and to acquire a linear regression between BNP and NTproBNP to identify its independent determinants. Methods : In 1032 consecutive patients, plasma level of BNP and NP-BNP were measured in a given patient for the evaluation of dyspnea or chest discomfort. Age, gender, body mass index (BMI), hemoglobin (Hb), and estimated glomerular filtration rate (eGFR), were recorded. In 967 of 1032 patients, we measured LV ejection fraction (LVEF), LV diatolic dimension index (LVDI), LV systolic dimension index (LVSI), LA diameter index (LADI), and E/E��� by 2D-guided echocardiography. Using ROC analyses, we compared the ability of peptides to identify LV systolic (LVEF <45% ) or advanced diastolic dysfunction (pseudonormal or restrictive physiology) and evaluated the potential influences of clinical, laboratory, and echocardiographic variables on the regression of BNP and NP-BNP by multiple linear regression analysis. Results : The area under the curve (AUC) of BNP and NP-BNP to detect LVEF <45%, advanced diastolic dysfunction, and advanced diastolic dysfunction with preserved LVEF were 0.909 vs. 0.893, 0.897 vs. 0.879, and 0.806 vs. 0.796 respectively. However, there were no significant differences of AUC between them. There was strongly positive correlation between loge-transformed concentrations of BNP and NP-BNP by linear regression (r = 0.895, r2 = 0.802, p<0.001). In univariate and multiple regression analyses (by stepwise method), plasma concentration of BNP, eGFR and LVEF were major independent determinants of plasma concentration of NP-BNP. The linear equation was Ln NP-BNP = 0.947 ��� Ln BNP 0.007 ��� eGFR 0.017 ��� LVEF + 3.098. Conclusion : There was no fundamental discrepancy in the diagnosis of LV dysfunction between both biomakers according to this head-to head comparison. In addition, eGFR and LVEF were independent determinants of plasma level of NP-BNP as well as BNP among all variables of interest.