SYMPATHETIC-NERVE ACTIVITY IN THE SPASM-INDUCED CORONARY-ARTERY REGION IS ASSOCIATED WITH DISEASE-ACTIVITY OF VASOSPASTIC ANGINA

Objectives. We assessed the relation between sympathetic nerve activit y and disease activity of vasospastic angina. Background. The autonomi c nervous system has been proposed to play a key role in attacks of va sospastic angina. A unique feature of vasospastic angina attacks is pe riodic fluctuation, which complicates the assessment of disease activi ty. Methods. Twenty five patients with left anterior descending corona ry artery (LAD) spasm were studied: 12 with recent onset of chest pain (group 1) and 13 free of angina for more than 3 months after disconti nuing medication (group 2). Group 1 underwent iodine-123 metaiodobenzy lguanidine (MIBG) imaging (in the active phase) and atropine-stress MI BG imaging early after diagnostic angiography, and repeat MIBG imaging when they were free of angina for more than 3 months with medication (in the stable phase). Group 2 also underwent MIBG imaging (in remissi on). On a bull's eye map, quantitative analysis of percent uptake and washout rate of MIBG was performed regionally. Results. In group 1 in the active phase, the washout rate of the LAD territory was significan tly lower than the rates in the stable phase, in remission and during atropine-stress MIBG imaging. The regional washout rate of the territo ries of the right coronary artery and the circumflex artery in the act ive phase was also significantly lower than that during atropine stres s MIBG imaging. The washout rate of the LAD territory in the active ph ase was significantly lower than the rates of the other two regions. I n contrast, there were no significant differences in the distribution of regional percent uptake in every image. A similar distribution of w ashout rate was observed among group 1 patients in the stable phase, i n group 1 patients during atropine-stress MIBG imaging and in group 2 patients. Conclusions. The MIBG washout rate of the spasm-induced coro nary artery territory changed according to the degree of disease activ ity, Thus, sympathetic nerve activity could reflect disease activity o f vasospastic angina.