[Clinical characteristics and coronary angiographic findings of spontaneous angina]

The clinical characteristics and coronary angiographic findings in 50 patients with spontaneous angina (SA) were studied. Coronary angiography did not disclose any severe fixed narrowing in 7 patients with SA only; the episodes of SA in these patients is the result of subtotal occlusion of a major coronary artery induced by spasm. 43 patients with both SA and effort angina (EA) had more severe coronary obstructive lesions. In these patients, the localization of electrocardiographic ischemia during episodes of SA and EA were always identical, indicating that the episodes of SA are related to the coronary narrowing lesions. Our study showed that incidence of SA was highest with 90% stenosis of the ischemia related artery, suggesting that besides coronary spasm, physiological coronary vasoconstriction or increase of coronary vasomotor tone could play an important role in the production of SA. In addition, turbulent flow, stasis, platelet aggregation and transient thrombosis might be individually responsible for episodes of SA in patients with severe coronary stenosis.