Positive provoked spasm in the left circumflex artery (LCX) is lower than that in the left anterior descending artery and right coronary artery (RCA).
We examined the provoked positive spasm in the LCX between the maximal acetylcholine (ACh) 100µg period (January 1991 to July 2012, 1474 patients: the former period) and the maximal ACh 200 µg period (August 2012 to August 2018, 336 patients: the latter period). ACh was injected in incremental dose of 20/50/100/200 µg into the left coronary artery and of 20/50/80 µg into the RCA. Positive spasm was defined as at least 90% stenosis and usual chest symptoms or ischemic ECG changes.
Provoked positive spasm in the latter period was significantly higher than that in the former period (65.5 vs. 39.1%, P<0.001). The positive spasm increase of RCA and left anterior descending artery was 143 and 159%, whereas the increase of LCX was 204%. Multiple-vessel spasm was also increased in the latter period.
Maximal ACh dose into the left coronary artery may affect the positive spasm in the LCX and multiple-vessel spasm.
aDepartment of Cardiology, Ehime Niihama Prefectural Hospital, Niihama
bDepartment of Cardiology, Tsukazaki Hospital, Himeji, Japan
Correspondence to Shozo Sueda, MD, The Department of Cardiology, Ehime Prefectual Niihama Hospital, Hongou 3 Choume 1-1, Niihama City 792-0042, Ehime Prefecture, Japan Tel: +81 897 436 161; fax: +81 897412 900; e-mail: firstname.lastname@example.org
Received December 2, 2018
Received in revised form April 4, 2019
Accepted April 6, 2019