Quantitative analysis of iodine 123 metaiodobenzylguanidine (MIBG) myocardial tomographic imaging showed that the regional uptake reduction and abnormally high washout of MIBG in the myocardial territories of the coronary artery with spasm were observed in 33 (75%) and in 30 (68%) of 44 patients with coronary spastic angina, whereas it was observed in two (7%) and in four (15%) of 27 control subjects, respectively. The patients with higher disease activity of the anginal attack and those with life-threatening ventricular arrhythmias were frequently associated with either the uptake reduction or the abnormally high washout of MIBG (91% in patients with high disease activity, 100% in patients with ventricular arrhythmias). The repeated studies of MIBG myocardial tomographic imaging at 2 and 6 months after suppression of anginal attacks by medical treatments showed that the scintigraphic abnormalities still remained in 85% of the patients at 2 months and 32% at 6 months. Thus the abnormalities in sympathetic nervous system assessed with MIBG scintigraphy has been shown to be highly associated with patients with coronary arteries with spasm, particularly high-risk patients, and lasted for several months despite suppression of anginal attack.