Unusual Vasospastic Angina: A Documented Asymptomatic Spasm with Normal ECG—A Case Report and a Review of the Literature

We report the case of a 53-years-old patient, known to have coronary artery disease, presenting with typical angina at rest with normal ECG and laboratory findings. His angina is relieved by sublingual nitroglycerin. He had undergone a cardiac catheterisation two weeks prior to his presentation for the same complaints. It showed nonsignificant coronary lesions. Another catheterisation was performed during his current admission. He developed coronary spasm during the procedure, still with no ECG changes. The spasm was reversed by administration of 2？mg of intracoronary isosorbide dinitrate. Variant (Prinzmetal's) angina was diagnosed in the absence of electrical ECG changes during pain episodes. 1. Background Coronary spasm is defined as a condition in which a relatively large coronary artery exhibits abnormal contraction (spasm). If the spasm induces a complete or nearly complete occlusion, transmural ischemia occurs in the region perfused by the artery, which in turn causes angina attacks with ST elevation on the ECG. If a partial occlusion occurs, or a sufficient collateral flow has developed distally, nontransmural ischemia occurs, causing anginal attacks with ST depression on the ECG. These pathological conditions are collectively termed vasospastic angina (also termed coronary spastic angina), as a type of angina pectoris caused by coronary spasm [1]. Variant angina pectoris, characterized by ST elevation during anginal attacks, is a type of vasospastic angina. Variant angina (Prinzmetal’s angina or periodic angina) is a form of unstable angina that usually occurs spontaneously and is characterized by transient ST-segment elevation that spontaneously resolves or resolves with nitroglycerin (NTG) use without progression to myocardial infarction, usually in the presence of coronary artery disease. Clinically, the patient presents with chest discomfort, mostly at rest without any preceding increase in myocardial oxygen demand [2]. The pathogenesis relies upon focal coronary artery spasm, in a single or multiple vessels, leading to transient severe transmural myocardial ischemia. In the present guidelines, the diagnostic criteria for vasospastic angina are established for three grades: “definite,” “suspected,” or “unlikely” [1]. Those criteria are provided in the discussion section. Typically, NTG is exquisitely effective in relieving the spasm. Coronary angiography is usually part of the workup of these patients and can help orient treatment [2]. 2. Case Presentation A 53-year-old male is admitted late morning for severe chest pain, with interscapular