Coronary Artery Spasm Provoked by Intracoronary Acetylcholine Administration

Shin, Won Sock; Lee, Myung Yong; Park, Seung Woo; Kim, Hyo Soo; Cho, Myeong Chan; Sohn, Dae Won; Park, Young Bae; Lee, Young Woo

Abstract

Acetylcholine provocation test was performed in 54 patients who were admitted to Seoul National University Hospital between August, 1989 and October, 1990 with chest painn and normal or near normal(narrowin of less than 30%) coronary arteries on baseline coronary angiogram. 1) After provocation with intracoronary acetylcholine, 19 patients showed coronary artery constriction of less than 50%, 5 patients showed constriction of 50 to 74%, 21 patients showed constriction of 75 to 99% and 5 patients showed total occlusion. patients with typical symptoms of variant angina showed coronary artery constriction of more than 50% in 81% of cases while those without such symptoms showed constriction of more than 50% in only 28%. 2) We classified the coronary artery constriction over 50% after acetylcholine provocation into focal, diffuse, combined type and total occlusion. 3) Branches of coronary artery on which constriction was provoked by acetylcholine were right coronary, left anterior descending and left circumflex in the decreasing order of frequency. 4) In patients with focal constriction less than 50%, there was neither ECG change nor development of chest pain, and out of 13 patients with focal constriction of more than 75%, 11 patients showed both chest pain and ST segment change and 2 of them showed either chest pain or ST sement change. 5) In 4 patients with diffuse constriction of less than 75%, we could not observe ECG change and chest pain and in 11 patients with diffuse constriction of more than 75%, six showed chest pain and ST segment change, four showed chest pain without ECG change and one showed neither chest pain nor ECG change. 6) In 5 patients with total occlusion, 3 of them showed both chest pain and ST segment change and 2 of them showed only chest pain. 7) Patients with coronary artery constriction of more than 75% showed significant difference in occurrence of chest pain and ST segment change in comparison with patients with coronary artery constriction of less than 75%(p<0.01). It is suggested that dynamic coronary artery constriction of more than 75% after acetylcholine provocation can be considered as positive test regardless of the morphologic feature of the lesion, whether it is diffuse or focal.