Summary:Coronary artery spasm: Use of ergo ovine in diagnosis. S. B. Freedman, R. F. Dunn, L. Bernstein, D. R. Richmond, G. O'Neill and D. T. Kelly,Aust. N.Z. J. Med., 1980, 10, pp. 6–11.Ergo ovine male ate was administered to 69 patients with chest pain but without significant coronary artery disease (<70% luminal diameter obstruction) to determine whether coronary artery spasm could be provoked. Coronary artery spasm was seen at angiography, or inferred from ECG or thallium myocardial perfusion scan changes. The test was positive in 76 patients: all five patients with documented variant angina (Group A); ten of the 19 patients with suspected variant angina (Group 6); one of the 11 patients with exercise‐induced chest pain (Group C); and none of the 34 patients with atypical chest pain (Group D). Patients with a positive test usually smoked, complained of recurrent nocturnal or early morning chest pain, showed ST changes during spontaneous chest pain and had minor degrees of fixed coronary obstruction (30–70%), when compared to those with a negative test. The only major side effect of the test was transient ventricular tachycardia which occurred in three patients and was reverted by sublingual and paranormal nitroglyc