BACKGROUND: The safety of ergonovine provocation for coronary vasospasm (CVS) performed outside the catheterization laboratory has been questioned. We sought to address the issues of safety, feasibility and clinical impact of noninvasive diagnosis of CVS. METHOD AND RESULTS: We retrospectively analyzed the results of bedside ergonovine provocation testing with monitoring of left ventricular regional wall motion abnormalities (RWMAs) by 2-dimensional echocardiography (ergonovine echocardiography, Erg Echo). After confirmation of no significant fixed epicardial coronary artery disease, 1,504 Erg Echo were performed in 1,372 patients from July 1991 to December 1997. Erg Echo was prematurely terminated in 13 patients (0.9%) due to limiting side effects unrelated with myocardial ischemia. Among 1,491 completed tests, 32% (477) showed positive results with development of RWMAs in 467 tests (98%) or ST displacement in ECG in 10 tests (2%). During the test, transient arrhythmias developed in 1.7% (26/1491) including transient ventricular tachycardia (2) and atrioventricular block (4), which were promptly reversed with nitroglycerin. There were no procedure-related death or development of myocardial infarction. On the basis of angiographic criteria in 218 patients, who also underwent invasive spasm provocation test during coronary angiography, the sensitivity and specificity of Erg Echo for the diagnosis of CVS were 93% and 91% respectively. From 1990 to 1997, total 2,073 spasm provocation tests were performed either during invasive coronary angiography in the catheterization or in the echocardiography laboratory. Since 1994, noninvasive Erg Echo became a more popular diagnostic method and comprised more than 95% of all spasm provocation tests in recent 3 years. Erg Echo was also performed safely in outpatient clinic setting without hospital admission in 34% (500/1491). CONCLUSIONS: Erg Echo is highly feasible, accurate and safe for diagnosis of CVS and can replace the invasive spasm provocation test during coronary angiography in the catheterization laboratory.