Background: NT-proBNP is a well known cardiac biomarker reflecting hemodynamic burdens and prognostic marker in patients with acute myocardial infarction (AMI). Many of patients with AMI present with clinical syndrome of heart failure with preserved left ventricular ejection fraction, and thus diastolic functional abnormality would be of importance in this clinical setting. The aim of this study was to investigate the significant diastolic functional parameters reflecting cardiac hemodynamic burdens as measured by NT-proBNP in patients with AMI. Methods: A total of 478 patients with AMI who had available images and could measure diastolic functional parameters including left atrial volume index (LAVI) were included the present study. The following diastolic functional parameters were measured according to the current guideline of American Society of Echocardiography; E, A, E/A, and DT on PW Doppler of mitral inflow, Em, Am, and Sm on septal tissue Doppler image, E/Em, LA dimension, LA area, and LAVI. The correlation between NT-proBNP and diastolic functional parameters were evaluated. Results: The level of NT-proBNP was 3246.3짹6822.6 pg/mL. The correlation between NT-proBNP and diastolic parameters were summarized in the table. The level of NT-proBNP showed significant positive correlation with E, A, E/Em, LA dimension, LA area, LAVI, and negative correlation with Sm and DT. However, Em, Am, and E/A did not show significant correlation with NT-proBNP. Among these significant variables, LAVI showed the most significant correlation with NT-proBNP. The correlation between LAVI and NT-proBNP was comparable to the correlation between left ventricular ejection fraction (55.7짹15.6 %) and NT-proBNP (r=-0.463, p<0.01). Conclusion: LAVI was the most significant diastolic functional parameter of cardiac burden as measured by NT-proBNP in patients with AMI. Therefore, the measurement of LAVI would be useful in the risk stratification or prognostication of AMI.