[Significance of retardation of abnormal uptake of iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid myocardial scintigraphy in patients with vasospastic angina].

OBJECTIVES This study investigated retardation of abnormal uptake of iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid(BMIPP) scintigraphy in patients with vasospastic angina. METHODS Twenty-three patients with vasospastic angina showed abnormal uptake of BMIPP before medical treatment and had coronary vasospasm induced by acetylcholine. The patients were divided into two groups according to uptake of BMIPP after medical treatment: retardation of abnormal uptake of BMIPP(Group R, n = 4) and normal uptake of BMIPP(Group N, n = 19). Frequency of chest pain, medical treatment and autonomic nervous activity were compared between the two groups. Furthermore, the frequency of chest pain and uptake of BMIPP in group R were obtained after intensive medical treatment. Autonomic nervous activity was evaluated by heart rate variability on Holter electrocardiography. Heart rate variability contained high-frequency elements(HF; 0.15-0.4 Hz) and low-frequency elements(LF; 0.04-0.15 Hz). LF/HF was estimated for sympathetic nervous activity and HF was estimated for parasympathetic nervous activity. Daytime and nighttime autonomic nervous activity were compared between the two groups. RESULTS The frequency of chest pain was higher in Group R than in Group N(p < 0.05). Medical treatment was not different between the two groups. Circadian variation of sympathetic and parasympathetic nervous activity were absent in Group R. During the nighttime, Group R showed higher sympathetic nervous activity(p < 0.05) and lower parasympathetic nervous activity(p < 0.01) than Group N. The frequency of chest pain was significantly lower after intensive medical treatment(p < 0.05), and uptake of BMIPP returned to normal in Group R. We suspected that the disorder in autonomic nervous activity was more severe in Group R, and thus induced coronary vasospasm. CONCLUSIONS Retardation of abnormal uptake of BMIPP in patients with vasospastic angina indicates poor control of coronary vasospasm. Uptake of BMIPP is useful in the evaluation of coronary vasospasm control in such patients.