Coronary Artery Spasm and Chest Pain with Normal Coronary Arteries

When evaluating acute chest pain, as in most other aspects of medicine, the foremost concern is with immediate life-threatening conditions; conditions that cannot afford to be missed. Although this role often falls on that of the emergency room physicians, it is essential for all to be aware of this acute differential diagnosis and the means by which to evaluate these conditions. In addition to acute myocardial infarction (AMI), life-threatening chest pain syndromes include aortic dissection, acute pulmonary embolism, tension pneumothorax, and esophageal rupture. Other serious conditions include microvascular disease, hypertrophic cardiomyopathy, aortic stenosis, myocarditis, pericarditis, coronary artery bridging, and coronary artery spasm. These conditions can present with a myriad of symptoms that at times makes them diffi cult to discern from acute coronary syndromes (ACS). When coronary arteries are referred to as “normal,” it implies that from a luminographic perspective, as seen with routine coronary angiogram, there appears to be no coronary artery disease (CAD). This normal appearance would include a lack of any visible stenosis or ectatic coronary arteries. To most cardiologists, chest pain syndromes with normal coronary arteries (CPNCOR) represent a diagnostic challenge. Ruling out signifi cant epicardial coronary artery disease is clearly not enough as other fatal syndromes need to be diagnosed and managed rapidly. A thorough investigation of chest pain is indicated in order to defi ne an etiology, initiate goal-directed therapy, alleviate patient fears, and improve functional status [1]. Although there are many methods of classifying the various etiologies of CPNCOR, one intuitive method is anatomical (Table 22.1): coronary versus noncoronary. Coronary causes may be further subdivided into epicardial diseases (including coronary artery spasm, endothelial dysfunction, and myocardial bridging) and cardiac diseases with coronary microvascular dysfunction