Coronary Artery Spasm: Basic Aspects

Coronary artery spasm plays an important role in a wide variety of coronary artery syndromes, not only in variant angina but also in unstable angina, myocardial infarction, and sudden death [1–5]. The prevalence of the spasm is apparently higher in Japanese patients with ischemic heart disease [5] than in Caucasians [6–9] (see Chap. 59). Since coronary artery spasm can be induced by a variety of stimuli with different mechanisms of action (even in the same patient), the occurrence of the spasm appears to be due to the local hyperreactivity of the coronary artery rather than to an enhanced stimulation with a single mechanism of action [10–12]. In order to elucidate the cellular and molecular mechanisms of the spasm, animal models of the spasm have been developed in the authors’ laboratory, the only working models of the spasm to date. In this chapter, recent advances on the cellular and molecular mechanisms of coronary artery spasm in the authors’ models are briefly summarized.