Microvascular angina: an update on diagnosis and treatment.

Many patients with chest pain who are relieved to learn that they have no obstructive stenoses at diagnostic angiography are misclassified as having noncardiac chest pain. Only recently have we developed the conceptual framework and diagnostic tools to understand that ischemic heart disease is not exclusively caused by obstructive coronary artery disease, but often has its origin in the microcirculation. This article will focus on the diagnosis and treatment of microvascular angina as a cause of myocardial ischemia in patients with abnormal but 'normal appearing' coronary arteries.