Role of single photon wall motion and perfusion studies in the evaluation of patients with suspected coronary artery disease.

Cardiovascular nuclear medicine procedures are useful to characterize coronary artery disease by measuring changes in perfusion, myocardial metabolism, cellular integrity, and regional or global function. Coronary angiography, while an excellent indicator of anatomic changes in arterial lumenal diameter, is a poor predictor of downstream perfusion, since neither the length of the stenosis nor absolute lumenal diameter is considered. Even if the anatomy is known, perfusion measurements provide information about ischaemia and ventricular dysfunction that is helpful for planning therapy. New technetium 99m-labelled perfusion agents are likely to improve the certainty of diagnosis due to their higher photon flux. The development of techniques for continuous ventricular function monitoring during daily activities provides an opportunity for detecting the impact of silent ischaemia on cardiac function. The role of the radionuclide imaging procedures in classifying patients with coronary disease is discussed in light of the pathophysiology of ischaemia and necrosis.