Angina pectoris and normal coronary arteriograms: clinical presentation and hemodynamic characteristics.

Up to 30% of patients undergoing coronary angiography for the assessment of chest pain suggestive of coronary artery disease have "normal" studies. Several reports have indicated that a proportion of patients with angina and normal coronary arteriograms have reduced coronary flow reserve. The interpretation of these findings is, however, controversial as the majority of patients do not have definitive evidence for myocardial ischemia and have a good long-term prognosis. The clinical presentation of patients with angina and normal coronary arteriograms differs in different series and this may be just a reflection of the heterogeneous nature of the syndrome. A diversity of pathogenetic mechanisms have been postulated to explain "syndrome X" (chest pain and normal coronary arteriograms) but little is known at present about the true nature of the syndrome. The present article discusses the clinical and hemodynamic features of this intriguing disorder with particular reference to patients with syndrome X and microvascular angina.