Coronary artery spasm: review and update

Abstract

Coronary artery spasm (CAS), an intense vasoconstriction of coronary arteries that causes total or subtotal vessel occlusion, plays an important role in myocardial ischemic syndromes including stable and unstable angina, acute myocardial infarction, and sudden cardiac death. Coronary angiography and provocative testing usually is required to establish a definitive diagnosis. While the mechanisms underlying the development of CAS are still poorly understood, CAS appears to be a multifactorial disease but is not associated with the traditional risk factors for coronary artery disease. The diagnosis of CAS has important therapeutic implications, as calcium antagonists, not β-blockers, are the cornerstone of medical treatment. The prognosis is generally considered benign; however, recurrent episodes of angina are frequently observed. We provide a review of the literature and summarize the current state of knowledge regarding the pathogenesis of CAS.

Keywords: Prinzmetal's angina; coronary artery spasm; provocative testing..

Figure 1

(A) Twelve-lead electrocardiogram in a 50-year-old male showing T-wave inversion in leads I, aVL, V_2-6. (B) Normal electrocardiogram after 6-month treatment with diltiazem. (C) More than 90% spontaneous vasospasm in the proximal left anterior descending artery (arrows). (D) The vasospasm was relieved after intracoronary administration of 100-μg nitroglycerin (arrows). (Reproduced from Hung MY, Hsu KH, Hung MJ, Cheng CW, Kuo LT, Cherng WJ. Interaction between cigarette smoking and high-sensitivity C-reactive protein in the development of coronary vasospasm in patients without hemodynamically significant coronary artery disease. Am J Med Sci. 2009; 338(6): 440-446, with permission of the publisher. Copyright © Wolters Kluwer Health, 2009.)

Figure 2

Twelve-lead electrocardiograms and coronary angiograms of variant angina. Chest pain attack (A) and post-sublingual nitroglycerin 0.6 mg (B) Twelve-lead electrocardiograms of a 47-year-old male patient who had variant angina show transient ST-segment elevation in the II, III, and aVF leads. Ten months later he underwent coronary angiography because of recurrent chest pain. The coronary angiograms reveal intracoronary methylergonovine-induced diameter reduction >70% in the mid-portion of right coronary artery (C, arrow), which was relieved after intracoronary nitroglycerin 200 μg administration (D).

Figure 3

Risk factors and precipitating factors for the development of coronary artery spasm (CAS). While risk factors, which often coexist and interact with one another, increase a person's susceptibility to developing CAS, precipitating factors may contribute to the onset of CAS and act in the same patient to cause angina in different conditions. The risk factors and precipitating factors are represented by rectangles and circles, respectively.