The diagnosis of coronary artery spasm in the cardiac catheterization laboratory.

Coronary artery spasm can now be well documented in the cardiac catheterization laboratory. At present, reliable criteria are available for the diagnosis of severe episodes that are characteristic of patients with Prinzmetal's variant angina. Newer criteria for the diagnosis of milder episodes of spasm are gradually being developed. Optimal criteria may become available with further progress of quantitative angiography. Provocation techniques for the induction of an attack of spasm in the cardiac catheterization laboratory are widely available. Of these, ergonovine testing is the most popular. The tests can usually be performed by experienced angiographers with impressive safety and provide a high degree of sensitivity and specificity when used in patients with the clinical diagnosis of variant angina. Although the research applications of such techniques are extremely broad, their practical clinical indications are somewhat limited to the work-up of patients with infrequent chest pains and normal or near-normal coronary arteriograms. There are other indirect methods for the diagnosis of coronary spasm, but the ideal technique is not available yet. Further expansion of newer modalities for the diagnosis of coronary artery spasm will certainly enhance our understanding of myocardial ischemia and will improve our ability to manage patients with ischemic heart disease.