Autonomic nerve function is involved in both blood pressure (BP) regulation and the pathogenesis of coronary artery spasm (CAS), but few studies have been published about the relationship between CAS and BP, with the exception of studies that explore hypertension as a risk factor for CAS. The purpose of this study was to investigate the incidence of CAS and atrioventricular (AV) block in association with BP level. The investigators will register consecutive patients who underwent coronary angiography with an acetylcholine (Ach)-induced provocation test from November 2004 to May 2012. The investigators exclude from the patients who were taking antihypertensive drugs or who had a documented history of cardiovascular disease in order to avoid the confounding effects of cardiovascular medications on coronary vasomotion. CAS is defined as >70% luminal narrowing on Ach provocation and /or concurrent chest pain. The study population will be divided into quartiles of rising systolic BP and diastolic BP. The incidence of Ach-induced CAS according to each systolic BP/diastolic BP quartile will be evaluated.