A case of vasospastic angina in which the ergonovine provocation test with intracoronary isosorbide dinitrate and nicorandil was effective in the diagnosis of microvascular spasm.

A 60-year-old man was admitted with early morning angina while at rest. Coronary angiogram revealed no organic lesions; therefore, a spasm provocation test with ergonovine was performed. Administration of intracoronary ergonovine induced total occlusion of the right coronary artery. The induced total occlusion improved but coronary flow velocity remained severely reduced and chest discomfort with ST-T changes in ECG remained in spite of repeated administration of isosorbide dinitrate (ISDN). Intracoronary administration of nicorandil following ISDN alleviated the chest discomfort, normalized the ST-T change in ECG, and improved the coronary flow. This suggested that microvascular spasm and the epicardial spasm were not relieved by ISDN but by nicorandil. Intracoronary nicorandil injection following ISDN administration may be useful for the diagnosis of microvascular spasm in the ergonovine provocation test.