スパスムを伴う狭心症例における運動負荷試験の臨床的意義

The role of the exercise test in angina pectoris associated with coronary arterial spasm

　狭心症における運動負荷試験は，狭心発作の誘発，虚血性ST変化の検出によって本症を診断する方法としての評価が定まっているかにみえる。冠動脈の器質的狭窄と運動負荷試験結果との関係についても詳細な検討がなされている^1〜4）。しかし，近年明らかにされつつある冠動脈のスパスムによる狭心症例についても同様の意義を有するか否かは明らかにされていない。そこで我々は，スパスムを伴う狭心症例における運動負荷試験と，冠動脈造影所見および臨床像とを対比検討し，その意義について考察を加えた。

Thirty-seven patients with resting angina pictoris and coronary arterial spasm confirmed by coronary angiography were examined. Coronary arterial spasm was evidenced by coronary angio-graphy during their spontaneous attacks in 9 patients or induced attacks by ergometrine maleate (26 patients) or hyperventilation (2 patients). Seventeen patients had history of effort angina as well as angina at rest.

Master's two step test and/or multistage tread-mill exercise test were performed in all patients. Twenty-one of 37 patients had positive exercise test. There was no statistical difference in the percentage of exercise-positive patients between those who had significant organic stenosis and those who had not. The location of ST changes in 21 patients with positive exercise test was identical to that during spontaneous attacks orthat induced coronary arterial spasm, and the site of ischemic ST changes corresponded to the loca-tion of coronary arterial spasm documented by coronary angiography. Among those with posi-tive exercise test, 12 patients had no significant stenosis, indicating that coronary arterial spasm could be induced by exercise test.