This book reviews the latest findings on epicardial coronary spasm and coronary microvascular dysfunction (CMD), important diseases for understanding coronary artery vasomotion abnormalities. The book chiefly consists of two major parts, each of which explores the epidemiology, pathophysiology, diagnosis and treatment of the diseases. The chapters present a range of experimental and clinical studies, including the editor’s life’s work on coronary spasm; how Rho-kinase activation plays an important role in connection with the disease; how chronic adventitial inflammation is a central pathophysiology of the spasm; the importance of Rho-kinase activation in the pathogenesis of CMD; how epicardial spasm and CMD frequently co-exist; and much more.