Two dimensional echocardiographic monitoring of left ventricular resional wall motion abnormalities(RWMA) with incremental injection of ergonovine up to 350µg(ErgEcho) is useful for a noninvasive diagnosis of coronary vasospasm(CVS). The prevalence that CVS may evoke unstable angina(UA). However, this theory has not been the subject of any systematic analysis to date. This prospective study was carried out on patients who had been tentatively diagnosed as having UA when they were carried out on patients who has been tentatively diagnosed as having UA when they were admitted to the coronary care unit due to chest pain. The aim was to determine the significance of CVS in the clinical spectrum of UA and the value of Erg Echo when applied to this situation.

With antianginal medications a diagnostic coronary angiography was done to rule out significant fixed athrosclerotic disease(FD), with more than 70% narrowing of luminal diameter. In patients with normal coronary angiograms of insignificant FD. Erg Echo was performed to diagnose CVS after the discontinuation of all antianginal medications. All patients with postinfarction or secondary angina were excluded in this study.

Of 191 patients(135 males, 57±9 yrs) enrolled from Mar 1992 to June 1993,71%(135/191) showed significant FD in the angiography. CVS was documented in 18%(34/191) using Erg Echo with mean injected ergonovine dosage of 125±89µg. In patients with CVS only 24%(8/34) had mild fixed lesion in the angiography with mean luminal narrowing of 60%(±12%). RWMA in the territory of left anterior descending artery was the most common(70%, 24/34). Other causes of chest were esophageal spasm in 3 patient(1%, 3/191) and hypertrophic cardiomyopathy in 2 patients, and 17 patients were diagnosed as having chest pain of unkwnon etiology. One of them redeveloped chest pain 2 months later. when repeated Erg Echo revealed RWMA. Others were symptom free during the follow-up(8±4 months) and there were no cardiac events.

Our data suggest that in patients presenting UA in Korea, CVA is the main cause of myocardial ischemia in considerable number of patient, and Erg Echo after the angiography is useful and safe for noninvasive diagnosis of CVS in this situation.