ALMOST 18 years have passed since Prinzmetal and his colleagues1originally described a variant form of angina pectoris characterized by cyclic attacks of chest pain occurring at rest and associated with transient ST-segment elevation. Prinzmetal postulated that these attacks were due to spasm of a major coronary artery. Recently, a number of investigators have reported coronary artery spasm occurring during spontaneous episodes of variant angina confirming Prinzmetal's hypothesis. Since spontaneous attacks of variant angina may be infrequent, specific tests for provoking coronary artery spasm in variant angina would be helpful in the diagnosis and evaluation of therapy in patients with this disorder. This case of a patient with classic Prinzmetal's angina illustrates the clinical presentation, current pharmacologic therapy, angiographic changes associated with pain episodes, an old but revived provocative test, and a new therapeutic agent for treatment of this condition. Report of a Case A 40-year-old woman was awakened at