Further insights into syndrome X

Chest pain with normal coronary angiograms is a relatively common syndrome. The mode of presentation of this syndrome includes patients with ‘syndrome X’ and patients with an acute myocardial infarction and angiographically normal coronary arteries. Several authors have attempted to categorise ‘chest pain with normal coronary arteries’ into distinct syndromes: cardiac syndrome X (CSX), vasotonic angina and ‘the sensitive heart’. Other authors preferred to label these patients simply as: ‘patients with normal angiography’. Yet, these terms are often used to describe a different situation for each group of authors. In the study of Chimenti et al the definition of CSX is ‘patients with chest pain, positive exercise test for myocardial ischaemia and angiographically smooth coronary arteries in multiple angiographic views’. Lanza et al defined CSX as a form of stable effort angina, which, according to careful diagnostic investigation, can reasonably be attributed to abnormalities in the coronary microvascular circulation even in the presence of near normal (<20% luminal narrowing) coronary arteries at angiography. Clearly, with this definition, patients with normal angiography are diluted with those with mild coronary artery disease in whom development of subsequent coronary events may simply reflect complication of coronary artery disease that was already present. Acknowledging that mild coronary artery disease is equivalent to normal coronary arteries is an assumption that is contradicted by recent data on the prognosis of those patients presenting acute coronary syndromes without angiographically visible lumen narrowing