Background: Ergonovine stress echocardiography (ESE) has been reported as a reliable noninvasive diagnostic method for coronary vasospasm. We evaluated coronary spasm in patients with acute myocardial infarction (AMI) with normal coronary angiogram using a ESE and compared the characteristics of positive group of patients with those of negative. Method: From May 1999 to July 2003, 49 patients with AMI (mean age 53짹12, 38 male) with normal coronary artery or non significant stenosis were included. The inclusion criteria were elevated cardiac enzyme and either ischemic symptom or ECG changes. ESE was started with injection of 50mcg of ergonovine (stage 1) with an increment of 50mcg every 5 minute to stage 5, with 100mcg at stage 6. Results: Among the total 49 patients, 29 patients (59%) showed regional wall motion changes during ESE. Among the clinical and angiographic parameters, myocardial bridge is more frequent in patients with negative ESE (p=0.037). Age, sex, alcohol drinking, basal wall motion abnormalities and risk factors (hypertension, diabestes and dyslipidemia) were not significantly different between 2 groups. Conclusion: Among 49 AMI patients with normal coronary angiogram, 29 patients (59%) had positive ESE and myocardial bridge is more frequent in negative group of patients compared to positive.