Abstract: To explore the role of the QRS interval for cardiac insufficiency in the immediate future following acute myocardial infarction (AMI). Methods120 patients with AMI for the first time were enrolled in the study and divided into four groups based on the heart function classification of Killip recorded within 72 hours after hospitalization. The density of brain natriuretic peptide (BNP) was determined in the plasma and the QRS interval was determined by electrocardiography. All patients were reviewed and followed up for 6 weeks and at the 6th week, the LVEF was determined by echocardiography. ResultThe QRS interval and level of BNP were increased by turns based on the heart function classified by Killip grade 1-4 and the differences were significant in each group(P＜0.01). The heart function classification of Killip in the acute stage following AMI positively correlated with the BNP and QRS interval(r=0.556 and r=0.385).　The log BNP and QRS interval were significantly higher in patients with heart failure than those in the control group(P＜0.01). LVEF of the recovery phase negatively correlated with the BNP and QRS interval(r=-0.577 and r=-0.502). The BNP＞596pg／mL and QRS interval＞100ms in the acute phase were both independent prognostic factors of heart failure in the immediate future following AMI(BNP OR=13.512, P=0.009;　QRS interval OR=4.696,　P=0.055).

Key words: QRS interval, Acute myocardial infarction, Heart insufficiency, Brain natriuretic peptide